This might have been an Apple/MS thing, but we always had very technical QA people on the dev tools team. For example, the QA lead for the C++ compiler had written their own compiler from scratch and was an amazing contributor.

> Moreover, the best QAs would almost always try to be not QA - to shift into a better respected and better paid field.

That sort of seems circular. If they're not respected or paid well, of course most of the talented people would not want to remain in QA, and eventually you'd just have mediocre QA. That doesn't really give you any insight into whether high quality QA would be useful though.

(edit: I see now that's basically the point you're trying to make, so I guess we're in agreement)

But yea, so many companies cheap their QA and then wonders why their QA sucks.