Wait, you think Sony should push for PS3 BC even though its virtually impossible for them to do so and that PS1 and PS2 are the long term goals?
You do know that it would be infinitively easier to port over PS1 and PS2 games right?
They have the source code and the data for the PS3, so I don't see how it'd be impossible for them to do so.
The PS3 architecture is designed in such a way that games coded for it are not automatically compatible with any other hardware. Its why you have seen devs remaster instead, because that easier than trying to get the PS4 to emulate something that is foreign to its own hardware.
its why its far easier for MS to implement BC because the structural differences between XB to 360 to X1 are close enough to make it possible. PS3 hardware is pretty foreign in terms of design. Why do you think so many devs had problems coding for it?
Its also why Sony went with a more user friendly and common architecture with the PS4 so that they wouldnt have software development issues from 3rd party devs. Likewise, PS4 is in a place to be forward compatible, something the PS3 will likely never ever be.