You have to remember that Sony don't have the rights to distribute all the content for a lot of the games on PS1 digitally, that is why they did not come to PS3 PSN in certain regions or at all. Also if there were certain bugs in games they would not distribute them either.
In saying that I would be in favour of combining the current PS4 and PS3 libraries on the next system. I have a lot of content on my PS3, and I don't really want to have 3 consoles in my TV unit.







