Teaches others humility by forcing a tank to gear how he (the healer) wants it or else.....
I'd agree with you if the tank was wearing some sort of disciple of war armor vs. actual tank left side gear. I am also going to assume your tank knows what a cool down is, because a VIT tank that doesn't know this is also a bad tank.
Marianno - I would encourage you to learn how to heal through these bad tanks and work to improve your skill as a healer. If you can survive a bad situation, even excel in one, imagine what you will be able to do when you get a good tank.