Here's a thought: Why should I spend my money on a game that needs to be fixed, when I can spend my money on a game that will be good out-of-the-box?
I actually kind of prefer things this way. It's similar to the Sims, where the graphics and game mechanics and everything are pretty simple (I think so that people can play on low-end computers), but you get this basic platform. And then through mods, you get to build your own totally custom game. Besides that, you can have your game so modded it becomes almost another game entirely, and if you want to, you can play through and then download different mods and play through again, and it's all free.
You can't make a game to suit everyone's tastes, and if there is a community willing to create and share mods, why not make a basic game that will appeal to a wider audience in the first place?
The way I see it, it pays much more to make a relatively simple game, but make sure it's highly moddable and release mod tools to get the community started than it would to make a highly complex game that is amazing (by the standards of one group) right off the shelf. PLUS, we get the benefit of buying one game that we can play on more affordable systems AND we can change anything and everything about it pretty easily. It seems like we'd be more limited in what we could do with highly complex and developed games, but iunno.
Of course, that's all for PC gamers. Console gamers just have to make a trade-off between the simplicity of an all-in-one game system and less game moddability, I guess.