Backwards compatibility is certainly an extra good point for a system, but it's not essential in the least, at least in my opinion.
As an example I own a PS4, I used to have a PS3 which I sold when I got my PS4
If last gen games mattered to me, I'd simply would have NOT sold my PS3, if I did it's cause I am moving on toward the PS4 cause I'm done with last gen. It's that simple.
Whereas remasters or remakes are a totally different thing as some remasters interest me and replaying a game I haven't in a long time but looking better and more fluid is good. Better yet, remasters and remakes can allow you to discover a great game that you missed in the previous gen, only looking better this time.