I still think Pat was overall right. Billy is NOT the norm for this kind of scenario. And while yes, he can still be a very good lancer at level 50, there's still no advantage to not going for dragoon or whatever as he could be doing even better, so he's still gimping his team, except he's good enough (and to be fair, DPS are not the classes that have sometimes required skills to make a run succesful)
But if it was a conjurer (like I play) for example who decided that for some reason he didn't want to become a white mage or a scholar, he would be a pain in the ass for higher dungeons as he would be lacking some really important spells