The fact that people complain about the performance of the mechanism that enables the system to be profiled, and so performance problems be identified, is beyond ironic. Surely the epitome of premature optimisation.
I don't see the people writing hyperfast low-level code asking for this.
My experience with profiling is anyway that you don't need that fine-grained profiling. It's main use is finding stuff like "we spend 90% of our time reallocating a string over and over to add characters one at a time". After a few of those it's just "it's a little bit slow everywhere".
And after that, you need fine-grained profiling to find multiple 1% wins and apply them repeatedly.
(I do this for a living, basically)
the funny thing is i am not sure if the world would actually work properly if we didn't have both of these kinds of people.