Put me down for another one of those who seems to have fallen away from gaming.
I've gamed for most of my life. Started with NES and owned consoles like SNES, Gamecube, Wii, Sega Megadrive, PS1, PS2, PS3 and multiple gaming PCs throughout my life. However, once I hit my late 20s (I am 33 now) my interest and patience in games nosedived. For the first time in my life, I don't plan to buy any of the next generation consoles (I hardly touched my PS3).
I boot up a game, configure my controls and graphics, look at the title screen..... and then log off. I think I have got 30+ games on my steam account that I have played like 10 mins max each. They are not bad games too (Batman AA and AC, Bioshock 1-2, Mass Effect 1-2-3, Civ 5, Borderlands 1-2, Skyrim etc) it's just that I no longer have the patience to sit in front of a screen and play through it anymore. I estimated that if I played all of my games which I haven't finished yet to completion, it would take me approximately 2 or more years at around 2hrs gaming a day. Last game I've really enjoyed was POE and that held me casually for around 3-4 weeks but haven't logged in for over 2 weeks now.
I think I've given up on MMOs. Nothing seems even remotely interesting on the horizon and too much of a time commitment even if it is.
Funnily enough, I've gone full circle. When I started gaming, I gave the argument that it was better than spending time watching the television. Now, I rather watch TV series and movies rather than game. Also, spending so much time sitting down playing games throughout my years made me very unfit. I am now finding more enjoyment spending time working out at the gym and getting into shape than playing computer games.
I would put it down to work commitments, family life and in general getting older and having more responsibilies. Maybe it will change in the future and I will enjoy playing games again with my kid (if and when I start a family) but I kind of doubt it.