Comments/Ratings for a Single Item

I can see two - make that 3 - reasons for not making a rules-checking preset. The first is so the players can easily substitute pieces without changing presets. The second is that the author is not computer/internet literate enough to do it. The third is the time factor; it may not be worth it to spend the time to do it - for me, this would inevitably be the case, as all 3 reasons apply to me. I have no desire to spend days trying to cobble together a preset that may or may not work. I've done it once with Zillions. The result was workable, but grotesque and unsatisfying. I learned nothing from it. It merely showed that sometimes poking something can get it running. For most reasonably simple games, I find it perfectly obvious what are and are not legal moves. And almost every game on this site is reasonably simple.  Why go to a lot of trouble for something that isn't necessary? 
Different people find different things easy or hard.

The easiest way of creating Zillions chess variant implementations is to choose the Fairy Chess alternative. Then you can right-click and set up any pieces in the initial configuration. For instance, you can set Nightriders in place of bishops, and a Fers in place of the Queen. When you are ready you save it to a gamefile that is named according to your variant name. When that gamefile is double-clicked your initial configuration will be immediately set up. This is a remarkably easy way of creating chess variants that are publishable. The only file you need to submit is the gamefile, and possibly a textfile with comments. If you want to create a 10x10 variant, choose the the Grand Chess variant. One can experiment with unequal armies this way, and it's an easy way of publishing fairy chess problems.
/Mats