Unless you have a parallel universe generator, I'm not sure how you could prove that sticking to the GPLv2 has been more successful than moving to V3.

Its success proves that GPL v3 was not needed to spur such success. That's not a judgement on whether v3 is "better" by some measure or other. It's a realistic measure that the modifications in v3 weren't needed for Linux to continue existing and flourishing.

  A != B does not imply that !B = A

Then I misunderstood what the GPP was trying to say, as it read to me that they were saying that Linus was right in sticking to the GPLv2.

My thought is that simply that he wasn't wrong, which is what you are then repeating back to me.

Unless Linus and the team want to re-write a bunch of GPLv2 kernel code (and modules), they are stuck with GPLv2 whether they want to change it or not. Linux is now over 30 and some of the original authors are no longer here to authorize a change in their copyright license.

https://lwn.net/Articles/169158/

Might makes right, after all.