Lack of mods in PC games is disappointing. Be it an FPS or RPG, modding adds life to games, keeps servers bolstered and can improve a game from mediocre to amazing.
Look at HoN or Counter Strike for instance. Those games wouldn't exist without modding. Look at COD4 vs any COD after it on PC. HORRIBLE. Look at the improvements people have done to Skyrim...I mean..c'mon!
Modding a right of passage for PC gamers..it's one of the main reasons a lot of us play PC games. If they gave us mods, but monitored what was being done with them in some way or made it so we couldn't imbalance the game I think it would make the game even better.