Earlier quoted context omitted.
GPLv2+ means you are accepting the terms of GPLv5. What's in GPLv5? I have no idea. No one has any idea. It might never get written. As long as RMS is in charge, I'm not worried about the contents of the next GPL dramatically differing from the current spirit. However, there is no guarantee that I will agree with future versions of the GPL. I'd like to judge them as they come. It's actually really strange to sign up…
> As long as RMS is in charge, I'm not worried about the contents of the next GPL dramatically differing from the current spirit. You don't have to trust RMS. You can trust lawyers interpreting clause 14 of GPLv3 correctly. This clause says that later GPL versions must be "similar in spirit". It also says that newer versions cannot impose any more obligations or restrictions on authors or copyright holders.
(Also, "similar in spirit" is so vague as to be completely meaningless.)