What is a better representation for playing a game is a verifyable fact, measurable by the average rating drop or raise people would get when having to play with one representation or another. E.g. representing all pieces by empty squares (aka blindfold chess) usually greatly degrades the rating of non-GM players, and can thus be considered an unsuitable representation for playing Chess.
Your example describes a handicap that would be universally detrimental for anyone playing against someone without this handicap. This points to some minimal requirements for piece design, namely that the pieces should be visible and clearly distinguishable. Both fully western sets and fully Japanese sets meet this requirement, and what makes the difference in how well someone can use one set or another will depend on more subjective, psychological differences, such as which set the person is more used to, or whether the pieces are written in a language one is able to read. Japanese people, and even Chinese and Korean people, will have an easier time with Kanji pieces than westerners will, because they can read the language the piece names are written in. Likewise, western players who are used to Staunton pieces will have an easier time recognizing pieces based on Staunton designs. To a lesser degree, western players may be less comfortable using wedge-shaped pieces than Japanese players would be. That is the preference you have indicated you have, though I have been playing with wedge-shaped pieces since I discovered Shogi in the late 90s and have no issue with them. So, my own preference is for pieces of a Staunton or my own Abstract design on wedge-shaped pieces.
And 'disagreeing with facts' is also known as 'being wrong'.
And what facts have you presented? You have not shown any data regarding which sets make it easier for people to play Shogi. The closest you have come to arguing for the superiority of western style Shogi pieces over Japanese style is this:
Playing Shogi across the board is an absolutely horrible experience. It is the main reason why the Dutch Chess Association has about 150,000 members, and the Dutch Shogi Association only 56...
While your data on membership counts may be correct, your explanation is not. This difference in membership counts is simply because the Netherlands is in Europe, where Chess is the dominant Chess variant, and not in Japan, where Shogi is. For similar reasons, you will find that Christian churches are more common in the Netherlands than Shinto shrines are.
For people that want to experience the difference between using pictogram and tile pieces, I set up a simple speed test cq dexterity game here.
So my response time for the pictograms is about half what it is for the Kanji tiles. But I'll point out that this is comparing two factors instead of just one. One is using either color or orientation, and the other is using Kanji or using pictures. Additionally, the Kanji pieces were at a smaller size, which made them harder to recognize, a more squarish shape, which made it harder to spot the orientation, and they included pieces not used in Shogi, which meant I could not always use my familiarity with the Kanji to recognize pieces.
The idea that Shogi and Chess would have different needs does seem rather inconsistent, as they are practically the same game. I have difficulty identifying any aspect of either game that would cause such a difference.
Two very big differences between Chess and Shogi account for this difference. In Shogi, pieces can switch sides, and promotion of each piece capable of it is to a fixed piece type. With wedge-shaped pieces that have different characters printed on each side, Shogi can easily be played with a single set of pieces. To play Shogi with western style pieces, you would need an extra set on hand, and each set would have to include separate pieces for the promoted and unpromoted versions of each piece. So, instead of requiring just 40 pieces, you would need up to 146 pieces if my calculations are correct.* Playing Shogi with fully western style pieces has become feasible only with computer graphics, which do not require physical pieces to be kept on hand. While this may be the preferred way for some people to play online or against a computer program, people with experience playing it across the board will have had to get used to using wedge-shaped pieces.
But it is indeed good that people can choose their representation on a computer independently of that used by the opponent. If there is at least one suitable representation amongst the choices.
That's the important thing. Some will prefer the traditional Japanese style, some will prefer a fully western style, and some will prefer a hybrid.
Your example describes a handicap that would be universally detrimental for anyone playing against someone without this handicap. This points to some minimal requirements for piece design, namely that the pieces should be visible and clearly distinguishable. Both fully western sets and fully Japanese sets meet this requirement, and what makes the difference in how well someone can use one set or another will depend on more subjective, psychological differences, such as which set the person is more used to, or whether the pieces are written in a language one is able to read. Japanese people, and even Chinese and Korean people, will have an easier time with Kanji pieces than westerners will, because they can read the language the piece names are written in. Likewise, western players who are used to Staunton pieces will have an easier time recognizing pieces based on Staunton designs. To a lesser degree, western players may be less comfortable using wedge-shaped pieces than Japanese players would be. That is the preference you have indicated you have, though I have been playing with wedge-shaped pieces since I discovered Shogi in the late 90s and have no issue with them. So, my own preference is for pieces of a Staunton or my own Abstract design on wedge-shaped pieces.
And what facts have you presented? You have not shown any data regarding which sets make it easier for people to play Shogi. The closest you have come to arguing for the superiority of western style Shogi pieces over Japanese style is this:
While your data on membership counts may be correct, your explanation is not. This difference in membership counts is simply because the Netherlands is in Europe, where Chess is the dominant Chess variant, and not in Japan, where Shogi is. For similar reasons, you will find that Christian churches are more common in the Netherlands than Shinto shrines are.
So my response time for the pictograms is about half what it is for the Kanji tiles. But I'll point out that this is comparing two factors instead of just one. One is using either color or orientation, and the other is using Kanji or using pictures. Additionally, the Kanji pieces were at a smaller size, which made them harder to recognize, a more squarish shape, which made it harder to spot the orientation, and they included pieces not used in Shogi, which meant I could not always use my familiarity with the Kanji to recognize pieces.
Two very big differences between Chess and Shogi account for this difference. In Shogi, pieces can switch sides, and promotion of each piece capable of it is to a fixed piece type. With wedge-shaped pieces that have different characters printed on each side, Shogi can easily be played with a single set of pieces. To play Shogi with western style pieces, you would need an extra set on hand, and each set would have to include separate pieces for the promoted and unpromoted versions of each piece. So, instead of requiring just 40 pieces, you would need up to 146 pieces if my calculations are correct.* Playing Shogi with fully western style pieces has become feasible only with computer graphics, which do not require physical pieces to be kept on hand. While this may be the preferred way for some people to play online or against a computer program, people with experience playing it across the board will have had to get used to using wedge-shaped pieces.
That's the important thing. Some will prefer the traditional Japanese style, some will prefer a fully western style, and some will prefer a hybrid.
* 40*2*2=160. 160 - 8 promoted Gold Generals - 4 promoted Kings - 2 normal Kings = 160 - 14 = 146.