I used to game a lot, got married 5 years ago so I played less games, had a kid 2 years ago so I played even less games. It's not only that I don't have as much time for games, but it's just that it no longer satisfies me either. Also, after some more trying days at work, I just don't care enough or have the energy to play, and I'm not one to play half assed games either since it'll make the small amount of time I play games suck even more. Lastly, other toys are better - why race on a computer when you can do it on a track?
Taste haven't changed, the world around me has.
It is interesting you mention that. I find my gaming tastes change because I want some story and I don't want to do a lot of thinking. One game that interested me was "Dear Esther", the game just told a story...no combat, no loss for dying, no puzzles, you just explore the world, enjoy the music, learn about the world and the story being told and then you get to the end. It was a really interesting and relaxing experience. It was like having a story read to you out loud, quite pleasant.
Maybe that is why older games appeal to us older gamers. We don't have to re-learn anything, you can just enjoy an experience that you are already comfortable. You don't need a large challenge because the challenge isn't what draws you in anymore...just a thought.