Like it or not, Glaumring, nobody has to pass a test to get into this game. Nobody is required to be a master roleplayer. Nobody is even required to be a good roleplayer. There are plenty of people—even among those who write lots of long RP messages—who are, in fact, atrocious at roleplaying their characters.
That is the case, it has always been the case, and it will always be the case. We cannot ignore it, change it, or pretend it is going to go away.
What we can do is try to make the game as fun and accessible as possible to people at both extremes—those who primarily want to roleplay being a medieval noble, and find this a good place to do that, and those who primarily want to plan out medieval wars, and find this a good place to do that—as long as they aren't trying to prevent people who fall elsewhere on the spectrum from also having fun.