That's fine, because it states the condition, rather than assuming it. If A says "Anyone who wants to study a MA should _______", he's probably stating a preference that doesn't apply to a significant number of people. There are exceptions ("Anyone who wants to study a MA should visit more than one school before deciding" is okay, because that'd apply to pretty much anyone).In the following discussion, does B have a point? (Please notice that A uses "one" and not "you".)
A: If one wants to lean how to fight, he has to fight.
B: You should not shove your opinion into my throat.