At the moment in FFXIV hate reset mechanics seem to be the "in" design concept to make boss fights artificially harder.
I don't think I've ever seen a MMORPG in which hate reset mechanics are overused as much as in this one, and in which hate is as hard (and often simply impossible) to get back once it has reset. And to be honest I've seen almost them all (all of the major ones and a large percentage of the minor).
The main reason why other developers don't use this mechanic much or at all is simply because it isn't fun, at all.
Not only it isn't fun (as making a role temporarily or permanently useless stripping him of all control is simply bad design entertainment-wise, and it doesn't happen to any other role in the game), but it also shifts the outcome of a battle much more towards luck than towards skill, as the lottery on who gets attacked next will often determine or will get very near to determine if the battle is won or lost.
On top of it, even counting games in which hate reset mechanics are (seldom) used, in none of them the tank is as powerless in getting hate back.
In other games when the hate resets a couple of aggro techniques like provoke and similar will bring hate back, forcing tanks to be on their toes but not making them feel powerless.
In FFXIV often, when the hate reset kicks, a paladin that throws ALL his hate-generating skills, has full enemity stacked gear and quaffs a maddening potion won't even go into the red.
That makes for the least fun fights I ever had in a MMORPG.
The solutions are simple (and a combination of them would be preferable).
1: abolish the use of hate reset mechanics on bosses, or at least make them the exception, not the norm. When creating boss mechanics be creative, not disruptive (IE: valorize people's roles instead of demolishing them. A good example is Raven, that valorizes the role of the ranged DPS by giving them something only they can do).
2: Give more instant power to hate generating moves like flash, provoke and the like, since, at the moment, they're little more than a whiff that the boss will mostly ignore. Getting hate back after a hate reset should be fast if one has planned ahead and kept his moves in reserve.
3: Give us more covering abilities or reduce the cooldown of cover by a LOT. If we can't be allowed to perform our role (which is silly to begin with), at least we should be able to block most hits against our team mates.
4: Put less (or none) emphasis on speed runs. Completing content quickly (and getting rewarded with less time investment) should be its own reward. Putting all the emphasis in doing stuff as quick as possible not only isn't fun (you got to skip cutscenes, and you don't have the time to enjoy the content), but it also forces the DPS to go all out all the time, turning getting hate back after a reset into a desperate task.
I've been a tank on every MMORPG I played since the word "tank" has been applied to multiplayer roles (which means since before MMOs came to light, with MUDs), and I honestly can't remember a single MMO in which tanking is more of a chore and less fun than this one after the enemity reform a year or so ago.
Holding aggro is our role, preventing us to perform it properly in so many boss fights doesn't make much sense at all.
There are so many much better (and more creative) ways to make boss fights challenging that this kind of role-breaking mechanic shouldn't be needed at all.