1.) Outdated graphics make it difficult to stomach
There was a time when I was astonished with games in the PS1, but it's interesting how some of us find it hard to play through old games anymore since we've been spoiled with graphics close to photorealism.
We used to rely on our imagination to make up for the blocks of pixels. However, our brain sort of raised the standard of what we want to see as technology innovates. Certain people can get past this especially if they have played the game before, but it's different if it's something you've never even touched.
For example, I grew up with the PlayStation console and I will gladly play Final Fantasy VIII and Resident Evil 3 again because nostalgia makes it easier to bear it. However, it'll be harder to convince me to play a game I don't know or from a generation I never got to be a part of.
Heck, I'm already starting to feel the age of the PS2.