I stand with consumers and players before the corporations, but we have to be realistic here. PS1 and PS3 games in particular would be an absolute pain in the ass to get running properly on PS5. A few hundred of them? Maybe. But expecting the majority of PS1, PS3 (and even PS2 games) is a huge undertaking in emulation and licensing.
The PlayStation family of home consoles has far more games digitally and physically than Nintendo and Xbox. That's all the more effort required to get most of them running on one console.

Lifetime Sales Predictions 

PS4: 130 mil (was 100 million) Xbox One: 55 mil (was 50 mil) Switch: 110 million (was 73, then 96 million)

3DS: 75.5 mil (was 73, then 77 million)

"Let go your earthly tether, enter the void, empty and become wind." - Guru Laghima