Some players can solo R10 or get through R10 with another good player or two. Then there's a lot of players who think they are of that calibre or trying to convince other people .... and they have it in their mind that they will only run R10. There's such a thing as R9, R8, R7 etc if you are accepting whoever hits the LFM. Either kick the people who have no business being there, or just take it down a few notches to get a smooth run.