Originally Posted by
Worshaka
Its not like the armor calculation is different for bears, armor is good for any tanking class in the fact that all tanks get hit 20% more often now makes armor even more valuable.
While armor appears to have diminishing returns it actually has a linear relationship with time to live, this is the main reason why armor is so tasty. In addition armor is gauranteed mitigation vs a chance to avoid, so it's benefits are not subject to RNG.
As you can see with warrior and pally T10 itemisation, they have been changed to incorporate more armor, this is another indicator how valuable armor is and you'll see a lot of the cutting edge tanks stack armor.