I realize i am a little late in posting this but if yo play a pally tank you are probably the least qualified to speak on this issue. I play all the tanks through at least 5 man content due to time restraints and ill tell you that your argument about some sort of ability is totally off point.

The biggest issue aside from avoidance and mastery directly contradicting one another is that the rune system is just busted and frankly just bad design. In general unless a bear or warrior screws up and spamms maul/heroic strike too much once combat has begun they have a virtually unlimited resource pool. Paladins get mana back at a pretty good rate during combat too. So none of the other tanks have to manage cooldowns on their abilities as well as cooldowns on their resource pool. While the rune system was a cool idea to begin with the changes in 4.0 made it into a frustrating hindrance that frankly well..yeah it sucks. I stopped playing my DK much after 4.0 dropped because the new system is so bad. The tree redesigns also made the DK class unappealing to me.