People don't hate tanks tanking here, the pace at which you are able to build strawmen is frankly astounding.
On the point of extra tanks in a party, if anything it would make fights harder not easier if we took the 75% tank damage value even. Lets take shiva as an example, if youre taking an extra tank for "safety" that means youre worried about being hit by avoidable mechanics, being hit by this in shiva gives you a hefty damage down, combined with the fact that youre still outputting less dps, youre going to at the very least have to deal with more mechanics which is harder than a faster clear time dealing with less mechanics. Also include the points i made about targetting earlier and youre making your lives more difficuly by taking more tanks.
On the point about enrages, the people youre hearing complain about tight enrages probably arn't experienced raiders or dont raid at all, a team full of basically competent people post week 2 or so will have the dps to clear. The reason why we want more dps is to feel more valuable towards lowering clear times further, its not just about beating enrage, its clearing fights faster and better, something which more damage allows tanks to have a greater influence on. With tanks on lower damage, you essentially can coast by because clear time is much more heavily impacted by your dps players and to an extent healer players (healers have the largest damage varience). Making tanks account for a bigger portion of the pie AS A STARTING POINT should the way to go for increasing relevance and satisfaction playing the jobs who want to optimise.
Finally your point on people flocking to warrior, yeah so? More people tanking is a good thing and warrior and drk were actually very close in terms of damage in heavensward, and having tanks be 70% of the damage of a dps didnt lead to dps being replaced in parties in the slightest