Provoke does not work in FATEs but it isn't needed. There are only three situations in which you can't maintain enmity as a tank in a fate.
1) Being severely undergeared. Tanks are expected to have good gear for anything, including FATEs. If the Bards have amazing gear, then you aren't going to be tanking anything and are pretty useless in damage contribution as well.
2) Getting to the Fate late. This is probably the only excusable thing because its not possible to be first at each one in a large place. People keep running towards the FATE areas ahead of time.
3) You died because there aren't Healers.

In situation 1, players are not going to hold back their dps for easy things like FATEs, and you shouldn't think people are going to stoop down to your level of damage when they aren't even part of the same party.
In situation 3, why would a Bard stand there if there are no healers? No one wants to die, its every man/party for himself. Kiting is easy and MOST mobs can't even touch you, including some bosses. They don't know everyone's enmity in comparison with their own except if the players are in the same party. If there are healers, then you can't trust them if they let the tank die.

If its a dungeon, HOW DO YOU LOSE HATE???? It's ridiculously easy to keep aggro on mobs, especially when you have Flash/Rage of Halone/Overpower/Provoke. You almost always have hate at all times if you are a good tank, and its still possible even when undergeared and players are dpsing hard. The fact that you are losing hate in the first place is your fault unless the most dire of situations happens. The Healer isn't healing you/died.

Fun tip, Bards can solo mobs through kiting. If a healer dies, they make things easier for a tank. If a tank dies, they make things easier for the healer to rez. If both die, they can potentially kill the mobs through kiting alone. If party is dead at chimera, they can kill it solo. Its a winning situation all around. Even the job quests pretty much encourage kiting and watching your surroundings so you don't attract more mobs will doing it.