Also, I have never seen any place where they get double of a developer's salary. They usually get a bit less than a developer of the same seniority, with enough variance for some places to pay a bit more.
I have no idea why games have those fucked-up development practices where dropping features or extending deadlines are prohibited (ok, I have some ideas, but little confidence on them). But it's not only QA that is degraded by them. Every single aspect of the development suffers.