Main Hand Item Level
Using job level as criteria is not valid because players are allowed to level multiple jobs
Since we don't really have a way to clearly tell what players are maining, using Main Hand Item Level to determine which jobs are being focused by players seems sound.
I know this is still flawed, but it's more reliable than comparing player job level
and if it really went back to tank shortage, that can still mean healer populations are still high.
Then the statement of "nobody wants to play healers" is false