Well, sometimes people buying carries aren't even bad players. They just either don't have the time to join competent raid groups or haven't found one yet and don't want to go through the hassle of being held back forever by bad PuGs.

But yeah, if you buy a clear and it was obvious you were carried, don't go joining farm parties until you get more practice. You'll get blacklisted anyways and then you've wasted your gil.