I like to think that the shortage is a good thing. I can start selling pro-tanking on pf for 100k a run.

Seriously though, the one and only reason is people get real life hate for tanking. Most people can't handle getting yelled at for playing a class. I love axes and swords so I guess I'm a tank in this game and people bitching at me is no biggie. So if someone starts cussing you out just drop out (and report, depending on the severity). Let them wait for a new tank, if one will que that is.