If they want to make tanks into more of a tank and less of a DPS, then they need to start by making things hit a bit harder. People weren't pulling 2-4 groups of mobs in dungeons and stance dancing in raids just to go quicker, they did it because its completely possible and easy to do it. I still will pull 2-4 groups if I know the pulls well and I know the healer/DPS are up to it, because a singular pull does so little damage I can forget cool downs and be just fine, just tax/anger the healer a bit more.

They also need more tank secondary stats. I tanked in SWTOR and they had 3 tank secondaries. One that was essentially parry, one that would affect how much damage you blocked through 'parry', and one that was for evasion. Meanwhile, we have tenacity, and the numbers haven't looked great from it yet. But even if it was, then it would mean we stack it, then fill in with DPS secondaries.

There's just no incentives to be tanky tanks in this game.