GPL has been battle tested in court
Well... parts of it have been. Others have not. Notably the FSFs view on whether or not linking to a GPL-licensed library constitutes a derivative work (and triggers the GPLs virality) is not universally shared by legal scholars. In the EU in particular linking does not necessarily create derivative works, despite what the FSF says. This has not been tested in court.
Some other parts like the v3 anti-tivoization hasn't gone to court either, but that has lesser ramifications (assuming you're not TiVo).
THAT'S how we have corporations profiting from GPL. Not because GPL allows anyone to use it.
What distinction are you trying to draw here exactly? They can do it precisely because the GPL (v2) allows it. The GPLv3 has some extra restrictions but doesn't do anything about closed source drivers (beyond the linking thing) or the Google Play Services type of proprietary extensions.