Tweaking guilt
I've occasionally tinkered with wargame rules. But after "improving" the game, I find it somehow unsettling to use my own house rules.
I guess the thing is, when I buy a wargame I feel I'm buying into a slice of the whole wargaming hobby. Hundreds, maybe thousands, of other people are playing the same game. And if I start playing it differently than everybody else, I'm on the fringes of the group.
Ironically, I play mostly solitaire anyhow, so it shouldn't matter. But even when I'm playing a solo wargame, I feel I'm practicing for the two-player game I'll play someday. And when that day comes, I don't want to have the rules wrong. In fact, my whole excuse for solitaire is that I'm just playtesting the game--learning the rules and getting the hang of the game system.