Ah yeah, I was playing Scholar the other day in a Tam-Tam run and the tank insisted on walking into one group of 3 mobs (at the start) and only using provoke on a single mob, letting the rest of us take hate, even so it was beyond easy to not heal, not enough damage taken, so from then on, the rest of us ran ahead and grouped up everything outside the boss area, even without the tank tanking, it was a walk in the park to heal and DPS, and it was much, much quicker and fun.

This pretty much applies to every dungeon afterwards.

Even at 90 it's so very easy to heal and DPS the entire wall to wall, but of course you need to be using mitigations, using job specific healing actions (often as tank I see WHM only Holy then regen and Cure 2, no lily use is insanely bad behavior) and dodge Area skills.

Nobody wants to pull one group of mobs and waste AoE's on just 3, when you can use AoE's on 9 or 12, that is like 15 minute or less runs, instead of 25 minutes or worse.