I agree that it has become a bit harder to play old games. Ever since I got a 64 bit operating system, it's been a pain to play old pc games. In the case of Tetris (I only play Tetris for Windows, 95, I think), I ended up installing a virtual machine to play it.
Other old games like LBA 2 had had some fans tweak it for 64 bit, although there were too many glitches to complete the game.
However, while it has become a bit harder, there still seems to be a solution to every problem. I haven't yet come across an old game that I simply cannot play. Sure, console companies don't make backwards compatible hardware, but you can get emulators on the PC that play most, if not all of the games from consoles going back many generations.
Also, even as consoles get more complex and difficult to emulate, PC technology and hardware continues to advance at a faster rate and should be able to keep up. Of course, there is always a lag before the emulator comes along, but I'm sure they will keep coming. I certainly hope so. It will be a sad sad day if we really lose access to old games. In recent times, I find myself returning to my old favourites far more often than playing new games.