The problem with sprint isn't actually sprint itself. The real problem is the high amount of long lasting CC abilities like heavy and sleep.
Most pvp games limit how many times you can be CC'd continuously (depending on duration). They also give melee tanks gap closers generally.

Combine the high amount of long range CC with the quick cooldown time of sprint- and that's when it starts to become an extremelly powerful defensive CD.

A lot of healers complain that they get killed really fast without being able to get any heals off. Those situations are usually because they are getting hammered by 3 other people. I'm going to guess said healers aren't queuing up with 2 black mages.

(Now dont get me wrong- I like sprint in pvp, but the current meta really favors trips casters over trips melee).