You'll never fix tanks by adding more damage, only by reducing the effort required to tank.
After 2 decades of tanking (I began my first couple of years as a healer) who pugs a lot, runs randoms with anyone and experiences various games' take on both tanking and dungeon finders I can categorically state that you won't increase the number of tanks just by increasing the numbers.
Tanking takes effort, more effort than dpsing.
Players want an easy option and pick that which requires the least effort - sure you will argue a few dont but that's why we have any tanks at all.
The only way to increase the number of tanks is give them an easier job than dpsing - forget taunts in randoms have every mob automatically taunted by the tank, so they 100% always attack them!
Coming from a background of enjoying high dps while tanking, I do tank less because of the low dps issue - but thats only after years of tanking in eso. What really puts me off tanking these days is I'm getting older and want to put the same amount of effort into the game as 95% of the player base - aka no effort.
And you can't do that as a tank.