I replied on this in a Matrix room already. I won’t retype my whole reply here. Essentially, IMO GPL stifles innovation as it forces everyone to use the same license and for everyone to release their code. This might be a good thing when it comes to concerns over competition (eg Threads vs everyone else), but it is a bad thing when it comes to building a community around a platform (theme developers can’t sell custom themes because they also have to publicly release their code under GPL. Plugin developers have the same issue. Technically, 3rd party apps should be releasing their code as well). Yes, there are many people who enjoy contributing to open source (myself included). However, there are also many that want to be recognized (financially) for their work. GPL ignores the latter. The fediverse already has a mechanism to guard against some corporation coming in and taking the code from a platform and building a commercial product on top of it - defederation. We don’t need GPL to “protect” us from anyone here).

NOTE: I also am not a lawyer. I might have some things wrong w/r/t GPL. However, I’m old enough to remember when it was actually an important OS license and when it was truly needed. I don’t believe that is the case any more. LGPL might be fine, but the rest of the variants should only be used after extremely careful consideration and not just as a default.