"the notion of counter-elites: those who are groomed for power and then excluded from it ... The tech industry is a better example ... Peter Thiel (classic counter elite Stanford-trained lawyer cum entrepreneur)"

Is what sense was Peter Thiel ever "excluded from power"? That's not my understanding of his career (but maybe my understanding is faulty).

More generally, is "wreak[ing] their vengeance by turning against the existing hierarchy" really a sensible way of thinking about the tech industry? Yes, the tech industry has certainly disrupted existing hierarchies in very significant ways, but it seems to me that the motivation there is not vengeance but rather profit.

Maybe I'm focusing too much on the word "vengeance". Is your claim more that there was significant "elite overproduction" in the 60's, 70's, 80's and 90's, and that absent this elite overproduction we wouldn't have the tech industry at all, or that the tech industry would be much smaller?