He doesn't have a problem with the GPLv2 allowing later versions, that's completely reasonable. His problem was that with the GPLv3 they changed the spirit of the license. He thinks a license "upgrade" shouldn't have done that, they should have just released a new license instead.

I.e. previously the agreement was "here's my code, if you change it send me the changes", now in addition to that it includes clauses about what you can do with the hardware you run it on.

I also don't want a future where all you can buy are locked-down devices, but is the GPL really the right venue to fight that battle? If companies want locked-down hardware they're just going to do lock it down anyway, and just use e.g. FreeBSD instead of Linux and contribute none of their code changes back.

Isn't it better that they release locked-down hardware but contribute their code changes, so that if someone wants to make competing open hardware they can start with all the same driver & feature support in Linux?