It is true that hate in other MMOs isn't usually a limit for people DPS'ing. DPS-er job is to output as much DPS as they can and tank usually don't have to worry about hate at all if their gear and macro rotation are correct.
However you do have punishing mechanics in place to prevent people just brainless spam couple DPS macros and be only like pew pew during a whole encounter, on top of "stay out of the fire" things that forces you to move.
Common mechanics such as:
- Reflective shield: You DPS, you kill yourself (and often in one hit). Or you may kill another raid member or even the whole raid.
- Regenerate boss HP: You DPS/do any action, boss cure HP. If your raid-DPS is low, you'll eventually wipe your raid because of enrage timer.
+ Add any kind of penalty you could receive by DPS'ing at the wrong time. From a lower max HP debuff, to a damage reduction penalty, buffing the boss or an add, etc.
So in the end, it's about the same. Tons of mechanics can be there to make DPS-er life hard and reduce their DPS output and make fight less monotonous for them. The difference with XIV is: you know exactly what impact any action will have in advance. You know that casting a spell while reflective shield is up will kill you. There is no guess.
On XIV, threat/enmity is obscure. You don't have any 100% accurate idea if casting a spell will or will not make you take aggro. We don't have any real formula either. If you want to max out efficiency, you' may end up in the "red" often, when drawing a line between "red" and "aggro (flashing red)" is impossible. With experience, you can approximate it, but that's about it. So you may take aggro.
If you never take aggro, does it mean that you were at 100% efficiency? Is there a way to know? Nope. You can't tell if casting one extra spell at any given time would or would not have generated enough hate for you to take aggro. So you have to try and be efficient, while having no way of knowing your exact limit.
I liked that in XI a lot (not being able to measure enmity etc.), but a lot of players don't.