The purpose of the GPLv3 was to address the "tivo" clause, where a vendor sells you a device with some modified GPL preloaded software included. You can request the software under GPL, but if you can't load it on the device then the FSF feels that's not very good.

So GPLv3 bans that. That, by itself, is inherently an additional restriction not allowed by GPLv2. They don't need to go out of their way or have a conspiracy to deliberately make it incompatible. Especially since the GPL2, as distributed and suggested, includes the "or later" text which resolves this incompatibility to allow GPL3 software to use GPL2 code. If anything, this encourages GPL2+ as the default GPL license if maximum compatibility is your goal.

Others (e.g. Linus), are more focused on getting the code changes so if they want to use them in the original project they can, and don't feel being able to install it on the device it was built for is as high up on the priority list.

Its also interesting to note that none of the GPL licenses require giving code back, so what Linus wants from the license doesn't happen via the license, only via cultural standards. Indeed, there are many companies and persons violating those cultural standards by not sending patches back to Linus, as well as many companies violating the GPL licenses by not distributing source to their customers.

A couple of interesting posts from Software Freedom Conservancy make it clear that what Tivo did (breaking proprietary software when reinstalling Linux) is allowed, even by the GPLv3 and that allowing reinstall of libre software is a requirement of the GPLv2 license.

https://sfconservancy.org/blog/2021/jul/23/tivoization-and-t... https://sfconservancy.org/blog/2021/mar/25/install-gplv2/ https://events19.linuxfoundation.org/wp-content/uploads/2017...