I don't know if its been said here or not.. 12 pages is a bit to read.

But Tanks just aren't needed after a certain point. Think about it, everyone who's doing something has their 2 tanks. That's right they only need 2. They need specific DPS classes to round out their statics and raids. This happens in most MMORPGs.

Sure the low level queues are lacking tanks, but at the top of the spectrum, they aren't needed as much. So those tanks switch to DPS and cause the cycle to repeat.

The problem is in the holy trinity itself. And more specifically pushing classes into singular roles.