How to get people to tank!

[Llus]

By the the time they would have gotten their tank stance lots of people have already given up trying to tank and started to play some other role instead.
Starting out difficult and then making it easier is generally not a good way of making people learn.

All research into learning shows just the opposite. People learn better when they're under stress and tanking and healing are both very stressful jobs. There are levels of stress that will make it impossible to learn, but you have to push yourself into uncomfortable and stressful situations in order to best learn. For those people who understand that and learn that lesson early, the more likely they are to pursue savage content because they understand that; while stressful at first they'll learn fairly quickly and be able to improve their game play substantially.