It's getting a bit out of topic but maybe I'll mention why I don't like to play mods so much myself. You get used to a great game, like Civ 4 BtS, and when I change it with mods, it seems I only get annoyed by not being familiar with the differences and just go back to playing the original. But that's over-simplifying really, most mods for strategy games make me feel like I'd rather be playing the original.
If the mod doesn't make me want to play the original, it just makes me feel like I'm playing a slightly different version of the same old, and I just get the sudden need to play a new game. I can blame Civ IV mods likes Rhye's and Fall of Civilization for making me just go "screw this I'll just get out and pick up an entirely different game like Europa Universalis III or Hearts of Iron or Sins of a Solar Empire or Age of Empires III". Anyway, hard to explain...
But I DO use some mods. Those I use are purely aesthetic or make the game more manageable (Varietas Delectas + BUG), so I'm all for a modding community.
It's a bit different for RPGs like Oblivion, where a large portion of mods actually add content without altering the rules of the game. But even then, I stay away from mods that give uber weapons to everybody and stuff like that. In a game like Civ, sure, you can add tons of techs and units, but the game mechanics become a lot more strained and stretched and some of its faults become more obvious.
So that's how I feel and why I don't play a lot of mods. But I see that modding communities certainly have an effect on the game developers and on sequels of certain game series, and that's a good thing, because let's face it, these guys can learn a lot from us

I am disgusted by companies like EA or Ubisoft, who make a lot (most?) of their games basically unmoddable. All hail Firaxis, Bethesda, Paradox Interactives, etc.