Sometime I hit provoke while waiting 2.5seconds to do something else, kind like a filler for boredom and It looks nice.

Sometimes I hit it to be adventurous and spice up my flash > 1 > 2 >3 > repeat combo (secret give us more skills request in disguise)

You will probably find a lot of tanks do it for those reasons above, they should change the tool tip or make it do what it says on the tin.