There is a nostalgia aspect playing here. The idea that we want games to be like the ones we were playing when we were at a certain age. As someone who feels (almost) no nostalgia that means very little to me personally and I sometimes find it hard to understand it from other people (e.g "Your first Mario Kart is your favourite Mario Kart.")
On the other hand there is the aspect of games changing rapidly at a certain moment in time. This is true of course and we can't expect games to be extremely innovative all the time but I don't necessarily expect the medium to only get incremental upgrades from now on either. Who knows what the future holds, especially in a medium as young as video games. Looking at the ridiculous technological leaps humanity has been making since the industrial revolution I'm confident that we still have a lot of potential to grow.
I'm much like you in that I don't really feel nostalgia, something I feel I can keep at bay because I play games from NES to today (seriously, anyone who thinks gaming was SO MUCH BETTER in the "good old days" has likely not hooked up their old consoles in a while....). Also, we have a tendency to remember only the best games of the older days while comparing that select portion with the whole of modern gaming. No one's going to remember Aliens: Colonial Marines, the same way no one remembers Little Red Hood of Secret of the Stars. The only way to be remembered is to be a really fun game or a hilariously bad one, like Big Rigs or Ride to Hell: Retribution.
It actually reminds me of a conversation I had with a Gamestop employee. He mentioned not having played Duke Nukem Forever and, when I mentioned that I had, asked me if it sucked as bad as everyone said. I actually said I'd prefer it if it had. It was a game that was competent, all the parts worked, but other than the tits on the wall in that one hive level, really didn't leave an impression. It's the sort of game I could see myself completely forgetting about in a few years, like I have with most of the NES', SNES, and PS1 selection, and I'm firmly of the opinion that it's not that much worse now.
As to evolution in gaming, I kinda look at it like a mine. When you find a place with some awesome mineral deposits and set up a new mine, you're getting precious metals up the ass. However, as the years go by and you dig in deeper and deeper, it gets harder and harder to find stuff, with only the occasional jackpot, but you're just as likely to cause a cave-in and get people killed. I feel that, with tech as advanced as it is now, we've dug pretty deep in the mine, so there's not as much innovation out there. Not only that, you might find the occasional awesome innovation, or even a fad, you're just as likely to do something catastrophically stupid and ruin your company. We'll still see some crazy innovations in the future, but the industry's mature, and just like with film and music, those innovations are going to be further apart.