I still ask, why is it your right to force them to play something else?
I played for years with someone who only wanted to play the fight. Simple, clean fighter. Sometimes different because of feats or weapon choice (two handed vs sword and board) but if he was happy, contributed to the game, was engaged with the other, and in the end was a good player in other ways why does this bother you or make it your job to force him to play something else?
I still do not see it.