I've seen the argument many times where tank dps priority comes from the fact that keeping enmity is so very easy, and yet optimized tank as of now requires actions by other roles for it to even work. The same applies for healer. In any case, the reason dps is being stripped or 'balanced' from the other roles is because it has literally become all that matters in terms of quantifiable skill. Not how well healers healed in less than ideal conditions or how a tank kept enmity despite the dps pouring out all they had but how much damage did you do? To be fair, the game itself has lent itself to mindset but this last expansion specifically it's gotten out of control when tanks die because healers are too invested in their dps to throw out a heal or tanks allow anyone who pulls aggro to keep it, regardless of circumstances, because dps stance best stance. Sorry bro.

Granted it really is a few bad eggs that ruin it for everyone but no one really bothered to try to educate otherwise becasue anyone who went against the almighty meta got visciously flayed. So sorry not sorry I guess? You reap what you sow.