You lost me, here.
Xperf and GPUview are tools I know devs use to check their code's performance, but that has nothing to do with the abstraction layer they are using, or any performance gains that are made using said layer.
Not to mention you are perfectly able to add code that is prone to the issues I wrote about above regardless of how you are building an application. Profiling your code in some ways helps you do this, because then you know exactly how long something takes, and you can use those timings to eke out more performance (and thereby introduce possible bugs related to timing).
Also, the very nature of code profiling means you need to have the hardware to profile it on - how do you propose developers do this on hardware they do not have? Make even
MORE assumptions? Your comment pre-supposes that the PS4Pro hardware was finalized
and available as soon as the PS4 was released, which I do believe is not the case...
I can't blame Sony for keeping their mouths shut about new hardware, I can't blame them for playing it safe in a market that crucifies you for anything that might possibly go wrong. I can't even blame them for not saying what amusing stuff breaks in their internal tests - that would have been amazing to see or know about.
I can't even blame devs assuming that hardware would remain static barring a generational leap, and coding straight down to the metal for that. No one foresaw this mid-gen refresh, barring some straight out psychic people.
I guess I am all out of blame.