What I don't get is how what they do is even legally possible, since the libraries have all F/OSS licenses (MIT, LGPL, GPL, APL), and they don't even own the sole copyright to most things.
You'd have to sue them to enforce it. Good luck bringing a case against Qualcomm, perhaps one of the worst companies known for its intellectual property management
Why do I need to sue them, when it's me, who does things I think are granted in their licenses, that they try to forbid? Isn't that the other way around?