Let me re-phrase that: slower because devs usually can't use it's full potential since it's a different system even for a console. Just look at games stuttering on the PS3 despite not being that graphically intensive (some need for speed game had this, afaik) or PS3 games having lower graphic quality than XBOX ones which is, afaik not the case normally, just because devs didn't write code for the PS3 but ported it because it was easier.
Still, I don't think it's only a small fraction of PCs that are faster than the PS3. PS3 is a powerful console, but how do you plan to compare it to PCs? By cores only, it wins, but there are many problems with parallelizing a program so sometimes raw power works better. I'd say a decent quadcore beats the cell in power, but not in flexibility.
Most people who game have a DX11 capable GPU, others have at least a DX10 GPU. Only a small fraction is still stuck on DX9 only, so it is worth it. You can see what not optimizing does, if your PC can play FFXIV on high settings, then you can play other games almost maxed out without problems.2- Every PS3 out there performs the same as another, a console engine can be exhaustively optimized for it and it pays off for every person who owns that console. What do you optimize a PC game engine for? There are tons of possible hardware combinations. The only certain thing is the deeper you go into particular optimizations for a certain combination of hardware, the more you will get diminished returns overall.
Even if they don't add DX10/11 features in the PC version, there still has to be room for other optimizations else i don't really understand where the whole processing power gets used.
Talking about PS3 optimizations now is useless, they can't even make a version that runs on the PS3 at all, so there is nothing to optimize.
And no need to get offensive there.
Well it was them who coded it, so it's their mess they have to clean up. It might be easier to rewrite some sections of code than optimize the existent one. It's up to them to decide that, we don't have the source code nor are we getting paid to get the work done.
Personally, I think they might consider doing something about it after they get the game to the point it's worth paying for. Optimization will help more people to play the game, especially those with slower systems, but it's going to take a while to implement the fixes