Well, let's say a newbie wants to ask questions about bitcoin. And finds out this forum, and he cannot ask because he has to learn first to sign a message or something. Won't he just say "fuck with this"? Or maybe even "fuck with all this crypto thing"?

So no, it's not feasible to log in like that. On the other hand, as said, we do have recover account with signed message; that is a much better use case.