Let's all count the number of fights we've won with that one dragoon mashing Full Thrust uncomboed. Or in spite of that Bard who thinks he's hot stuff and can judge the rest of the party's performance while underclocking by over 50%. Let's count the number of real wipes that causes in an encounter.

Let's call count the number of fights we've won with that one White Mage only spamming Medica and hollering "SHROUD IS AN AGGRO MANAGEMENT TOOL" while out of MP with a tank dying. Let's count the number of real wipes that were caused by two idiot scholars stepping on each others' toes with Adloquium while neglecting an OT or the rest of the party or even each other while their Eos' spam unmicroed Fey Illumination right on top of each other.

Talk about skill ceilings all you want, but healing has the highest skill floor in the game. Until top level content, DPS can coast and all tanks need to know is to press 1-2-3 and not drive the mob car directly into the party.