On the artistry side there is more : 20 years ago (ouch) you still had mainstream games that were built without too much of marketing pressure. I remember an interview of a Warcraft 2 team member who was saying that they were simply trying to make the best game for themselves. So sure there is nostalgia, but when comparing mainstream the difference is not just technical. Same as in music, the (edit: artistic) quality is now in the indie, and thanks to great tools it's a better time than ever for creativity, at the expense that it's harder to live from it.
