The current monk was the result of a series of bad decisions, and 5.1 made it worse

[Shurrikhan]

With all the prerequisites, then you could use the TK rotation. So, in theory it was only a 30s CD on a dummy fight. Just to add as well to how weak tornado kick is even when used optimally - in E3S where it sees up to 3 uses it's only about a gain of 100dps...

And Chaos, and Midgardsomr, and Omega (top parse is actually more often than once every 30 seconds), and nearly so in Omega-M/F, and again in Final Omega, and before that Doomtrain, Phantom, Demon Chadarnook (top parse again more often than per 30s), nearly per 30 on Guardian (likely due to finally actually needing ST for movement), and again on Kefka...

Oh wait, that was... every Savage fight since Riddle of Wind, almost all perfectly per 30 seconds minus jumps, and a few more often than per 30s.

Its prerequisite may have been tied to the cooldown of a different skill, but it objectively was used per 30 seconds in optimal play; as if merely used on (RoW's) cooldown.