Nobody cares.

I wouldnt give a shit. I got ps4, yes, but i kept the ps3 and we use it as a dvd/bluray player.

This would be my reaction

If the PS4 would have been BC from day 1 it would have costed quite a few PS4 games that were purchased to not have been purchased. There is no doubt about that.

I would bet $5. The Last of US Remaster still would of been made and sold like it did. If BC was in the system. People care that hard about real 1080p 60fps. It's why companies are screwed up as it is now.

I would be surprised... and most likely won't use it beyond maybe checking out GT6. I still have my ps3 hooked up, but don't use it for games anymore. I did want to play GT6 again a few weeks ago, but after a 3 hour update I had forgotten about it again.

Getting PS3 games to run on PS4 isn't impossible, it's just a very complicated process and would require a fair amount of work.

1st of all you have to deal with the core issues that the PPC in PS3 uses RISC assembly language and the SPEs use it's own custom assembly language which is called ISA.
The code that runs on both of those processors in PS3 would need to be re-written or recognized as X86 on PS4.

PS3's SPE code could be offloaded to PS4's GPU in Backwards Compatibility, leaving a substantial amount of overhead CPU available for any tasks that need to deal with PowerPC processes.
PS4's GPU is substantially more powerful than the RSX.

Overall Sony could very likely write an emulation environment, basically a virtual PS3 to run on PS4's SOC.
Emulation handled in this way isn't the only possibility, Sony could re-write each game that users request, place a patch on servers for users to download when they're connected to the internet, though this is likely the more time consuming possibility.
I don't see why The ICE Team or some other development team that is familiar with PS3 and PS4 hardware, OS and APIs in both systems couldn't make a truly virtual PS3 that can run on PS4, it all just depends on whether Sony wants to make this work or provide the resources to make it happen.

Backwards Compatibility doesn't get in the way of PS Now, because the whole idea of PSNow is to be used as a rental service for people that don't own all of the games in the PS3's library or even for people that never owned a PS3 in the first place.

BC could allow Sony to sell more PS3 games, if people want a superior experience then the remasters and remakes will also sell, so really it's all money for Sony.

As for my reaction, I'd be impressed that Sony were willing to put the resources into this, though it's not impossible despite what some claim about this.

Mostly indifference, but would at least have an excuse to pull a few PS3 games out of storage.

I pretty much made a point of transitioning off the PS3 back in 2013 as far as new games go making the PS3 nothing more than a retro gaming system for me today.

That said, I do have two PS3s with HDDs loaded with games installed, yet they're in storage which confirms I'm over the platform similar to the way I stopped playing PS2 games on the CECH-A01 about 2-3 years into the PS3 product life cycle.

I know some people who would want that, but personally, i'm fine with just playing PS3 games on my PS3 :P

Largely a waste of resources to do individual compatibility porting of PS3 games given SCE already invested in PSNow and that most of the biggest PS3 games are seeing PS4 remasters.

Naturally, this is not ideal for consumers like myself who have close to a hundred PS3 retail games and over a hundred more on my PSN account, but it's not as though I play any of those old games anymore. It just means I need to keep at least one working PS3 in storage for retro gaming.