Show me any shitty tank that can solo tank a fight in ToT (let's make it H) and i'll give you a cookie.
The entire point of solo tanking a fight (or doing w/e other veng shenanigans) is that you don't just get it by being attacked, you get it by carefully using your CD's so you don't get gibbed.
Otherwise healers just wouldn't be able to heal you through the damage (and even if they could, that would qualify as "through hell and back" for healers).
We don't know how that haste and mastery will affect us in 6.0The consequence is the same, you're still getting haste and crit no matter what the name of the stat reads on the item. I mean, I always saw Vengeance and AM as a 6.0 discussion, obviously reworking the entire system at this point would take a lot of effort and break old fights.
If we're here to discuss 5.4, well, I could care less.
Hell we've had it in cata, and yet i haven't seen tanks using "dps" gear (bears excluded) so their dps can go up.
If blizzard actually wanted to make both active and passive mitigation useful they could. Make passive give 0.x of haste/crit till it's competitive but not yet superior, bam, you get to pick more mitigation for slightly smaller dmg output.
Now you get to pick between better mitigation + better dmg vs worse mitigation + worse dmg.