I think it's fair to say that this generation has seen the most games ever dumbed down in an attempt to conform to industry standards. The stealth genre, for example, is virtually dead, aside from a 1-2 games. Socom, Splinter Cell, and now Hitman have stripped away many elements that made them unique. They have been replaced to make the games more accessible. Developers always say, "we're trying to appeal to a larger target audience,' but what this always means is, "we're dumbing the game down." Things like freedom and uniqueness have been replaced with linearity, conformity, and a focus on presentation rather than actual gameplay.
Who do we blame for this? I blame everyone. I blame Nintendo for the Wii, motion controls, Wii Fit, and every other casual title they've release that's been a huge hit. I blame Microsoft for Xbox Live which allowed Call of Duty to shine and become the standard that other developers try to replicate. I blame Sony for making games like Uncharted and God of War which influenced other developers to tackle cinematics even when it didn't match the gameplay. I blame everyone, developers, console manufactuers, consumers; everyone has contributed to the Casualization of this generation which has ruined some of the most beloved franchises of past generations.
Don't get me wrong, I have nothing against games like Uncharted, Call of Duty, or Assassin's Creed for being targetting toward the mainstream. I'm upset with the general trend of the entire industry. Games that were formerly deep or complex are being simplified to be another Uncharted or another Call of Duty. Games are beginning to look more and more alike, just with a different coat of paint. It's a shame really. So many unique experiences...gone.