Yep, Provoke probably the most misunderstood ability in game. Or at minimum the most misunderstood tank ability.

Provoke gives you slightly more agro than the person currently at top of agro list. And I do emphasize the slightly part. Like +1 point, which ends up being ~0.0001%. So any activity at all done by the person 2nd on agro list puts them to 1st (i.e., person using Provoke loses agro right after).

Want to pull at very long range - longer than Tomahawk/Shield Lob? Cool. Use Provoke.
Want to pull 1 mob with GCD ability, and another before GCD finishes? Cool. Use Provoke for one of them.
Want to grab hate of a mob that's attacking your party member? Cool. Use Provoke followed quickly by another ability (Tomahawk/Shield Lob possibly).

Anything else - like using Provoke when Tomahawk/Shield Lob would work, or when you already have top agro spot - is just useless waste of the Provoke skill.

Having a thread like this trending on the forums might help. At least for that faction of players that actually reads here.