Only way for me to ever tank in any mmo not just wow is if developers go full on Firefly Alliance and try to change human nature with some sort of gas.
I have better and more fun time as dps than acting as a human toilet to maniacs who lack any human decency.
Because they did not tie the defensive rotation of the tanks to said dps. They just flat buffed the damage of abilities.
And they keep doing the same thing with healers and running into problems.
If you gave all tanks some sort of “thorns” it would be a different story. And of course, you elimitate the issue of “running a key with 5 tanks” because only 1 of them can be hit. The others will just sit there doing horrible DPS.
They should revert the keychanges from DF season 4. It pushed me out of M+ as a tank. No more lower keys till you are comfortable with +15 for example is a bad thing. Catering to the top 1% seems the new road ahead for blizzard atm.
That being said: 99% of my gear comes from +8 groupdelves right now, wich wasnt my plan for this expansion.
Bro i dunno what game you have been playing but nobody likes to heal or tank in games and if they do it its because of fast que, if blizzard wants to fix this and make people play tanks they need to buff the hell outta them so they can pull large amount of packs just like it was in Legion or BFA.
Some of us love playing as tank and/or healer.
The main reason we don’t sign up for m+ keys on these roles however is not because we don’t like to play as tank/healer, it’s because people treat us like garbage.
Congratulations you are now the 1%.
Even if M+ were less punishing than it is this season there would still be a tank shortage. As it’s “one of”, if not “the most”, “important” role in a group - and the leader - the party is so damn quick to flame/rage whenever the role model/leadership figure make a slight mistake.
Contrary to popular beliefs, people are not cut out to take such flame, and thus revert to the role that least sticks out of the crowd - dee pee ess.
Or it could be it’s just the more fun (and relaxing? not imo) role.
where’s my 100 million gold?
I mean, you just described how vengeance used to work for tanks during MoP (the passive, not the spec).
And while it was fun for tanks during raid, it turned into a problem quite fast.
I love playing the support class in any MMO/RPG… this character used to main as a healer, primary reason why I became a Priest – the “go to” healer in any RPG.
Time to team up and run dungies together!
Key word “used to” … I’ve not healed since Legion 
sadge
Sorry bro only pain and suffering for the role that you have…
And what was the problem ? That tanks abused it by changing to DD stance and wrecking the DPS charts ?
Its what happens if you apply 1 single mechanics to 6 tanks with diverse playstiles.
If you were to do the same with healers, you would simply give atonement to every healer. And of course, would create chaos.
What you should do is Atonement for DPriest. Ancent teachings to MW monk. To RShaman some sort of feeback loop that healins spells reduce the cast time of damage spells and vice versa… Things along those lines.
So what they need to do is give vengence to Blood DKs for example. But to druids some other mechanic of transforming mitigation to damage.
If that damage done depends on damage taken it could work(like warrior revenge)
This was the most idiotic mechanic of old 
I hope they will never bring it back
The issues i have with playing tank - half of them are in unhealthy APM range, their rotations are bloated and they have to spam short duration short cd skills that increase their defense, when that effect should be passive and they should only use larger cds for larger large damage events
In Dungeon you need 1 tank 1 healer 3 dps
In Raid you need 2 Tanks all the time Healers 2-6 and up to 22 dps
That’s why you have issues to find a Tank
But this problem isn’t new
You totally have reason, then why with my 2k5 score i’m declined on 10 keys i already timed (and i’m playing drood tank) ?