Why not? I hope you're right obviously, but considering we have a subscription for PS3 games on PS4 and PS2 compatibility died on PS3 consoles in less than a year, not sure I'm feeling this.
Because PS3 is a completely different architecture from PS4(with the Cell, SPU, RSX, and split RAM combo) and could not be possibly emulated on the machine natively unless they actually put cell into the PS4, which was never happening. The console does not have the processing hardware to emulate it, no PC does at this point either.
PLaystation now was their way of expanding their library while also providing some sort of stop gap measure for playing PS3 games without PS3.
PS4 with X86 and a direct architecture timeline from here to 2019 with AMD means they can easily provide BC if they prioritize simulating the base hardware.
The Pro is mostly not native 4k and it doesn't break backwards compatibility with the PS4. An 8 TF system as the person I responded to quoted wouldn't really be good for a generational transition, because the 6-8 TF range is about where you need to be to give the games we're already getting now in native 4k. Ergo, you'd want a lot more than that.
We aren't getting native 4K games AND next generation graphics next gen no matter what happens. You should prepare for that.
It will be one or the other. I don't expect 8tflops btw, i expect 10.
Pro is a 4K compliant machine that is a half gap measure. It meets expectations.