Either finance, or lack of interest.
If someone is totally uninterested in newer games or perhaps software in general, they just don't have to upgrade. For some, the oldschool feeling of say, windows 98 is fine with them forever.
Personally, I think I've stopped with upgrading my comp for a long while now, since I got my new video card more than a year ago. Most newer games don't really have me in mood to play, besides, I can't really afford to keep upgrading.. my family is doing rather poor financially nowadays, so it would be rather irresponsible to weigh on us even more.
Now, to contribute to the topic, what I last did was:
Mess around with Java. I've been trying to make a 2D platformer style game, mostly with the purpose of learning. I've learned a lot so far, but I always keep running into epic problems
.. but before I make several shitty songs, I'll try to get it play some proper free-to-use remixes





