Plenty of people are happy with video games exactly as they are, and more of the same is just fine by them. But to those who are truly passionate about games as the century's next great entertainment medium, we're nowhere near done yet.
Here's a theory that's getting too popular to ignore: Games don't meaningfully evolve because the population creating them never changes. Kid grows up playing certain types of games, and then he becomes an adult, who makes games for other people like him.
He's part of a team that shares his same general background and interests. The result is that a massive swath of game developers are a similar type of person, and that most games are created by that type of person, for that type of person.
Not only does that insularity limit gaming's audience and exclude other potential players, but it's a model that resembles genetic inbreeding, and as such has the same consequences.
When inbreeding happens in nature, for a few generations, certain desirable traits are emphasized. But it comes at the expense of others, and then beyond a certain point, homogeny begins to weaken the species. Sameness kills. Diversity is necessary to sustain life - and this is true in art as well as in nature.
We don't just love indie designers because they're quirky and scrappy - we love them because their freedom from corporate constraint and their relative disinterest in mass-market appeal results in games and creative expression we just don't get in the mainstream.