Let me start off by saying I enjoy playing the tank more than any other role in a themepark. I enjoy the challenge, I find the gameplay more entertaining, and well, I’m not a droolcup so playing DPS would be a waste.
But if you want to know why there is a tank shortage, just watch a tank’s screen during some boss encounters. It’s not a whole lot of fun to have a 24” ultra-bright monitor become a techno rave for 5-10 minutes because the boss is so close to you that you’re inside his crotch, and those fancy effects and great animations he has become screen-filling single-color flashes of nausea-inducing nothingness. Now a single 5-10 minutes stretch is one thing (it still sucks, but at least the suck is limited), but repeat wipes on Mr. Techno? No thanks. An instance where it seems every boss is Mr. Techno? I’ll come back when we can steamroll the place just to see it once.
The bad solution would be to make bosses stationary or move on a pre-set pattern. That’s a cheap way out, and would limit encounter design way too much. Not that I don’t appreciate those types of bosses, I do, and they certainly make nice breaks from crotch-viewing, but it’s not the long-term solution.
The long-term solution is collision detection. Why is it that devs only consider this important for PvP, and even then it’s pretty rare to see it done right (ie: Darkfall)? With collision detection not only would you stop the boss from standing on top of a tank, you could also do a whole lot more with encounter design. Narrow corridors would matter, getting knocked into a corner would matter, and positioning would be a lot deeper if you had to consider where your teammates are running. A giant boss would actually be a giant obstacle instead of yet another mob that the tank finds himself half-way inside of.
Until then, I’ll keep the Advil close at hand.