. Steam(sux) doesnt allow modding.... every time the game is launched it restores the files to the original state... so any mods i made go to waste.. i hate that... i love modding... and i will never buy from them just for that...
My Left 4 Dead mods folder begs to differ. I think you're talking about patching the executables, and if they patch the files, you'd still need to update your mod anyway, if only to make sure it still fits where its supposed to. Personally I like the fact that they keep the game up to date automatically, although I can see where that would be frustrating for custom patching.
Anyway, you should have a look at Sins of a Solar Empire, another Impulse game. There are plenty of mods out for it, and it only updates itself when you tell it to.