FOR ONE SPEC. Did you not read that part? I'm fine with having separate gear for another spec
I'm sorry. Several years of carrying gear for two specs and only using one spec and using "Ret" gear in Protection spec kind of dulled my senses to your proposition that a tank would have to carry a complete third set of gear. That your 2nd spec set using a completely differnt primary than your tank spec is a choice you deliberately made, and is a choice that's not even available to half the tanking specs anyway.
What you seem to suffer from here is a complete and overbearing case of gross generalization.
Does this actually require pretending? Well, the first part does, but I thought the second part was where we are *now*. And it was Blizzard contemplating rolling that back and making us all go back to stacking avoidance that prompted threads like this.
What tank performs best by stacking avoidance stats right now, in 5.1?
Honestly? Warriors do, depending on what your basis for comparing "best" is. More avoidance is more Revenge is more rage for Active Mitigation. Is it the best strategy for a warrior? No, but it works better for a warrior than it does for any other tank, and therefor makes Warrior the spec that perform best by stacking avoidance.
If they were to roll Dodge and Parry into one Avoidance stat, and throw +Armor on tanking gear, I'd be fine with that. If they were to completely reinvent avoidance completely and keep the same name, like they did with Spirit, I'd be fine with that. The problem with what a few of you are proposing is that you aren't just saying to get rid of avoidance. You're advocating supplanting avoidance with DPS stats.
Crit is neat. Crit is fun for everyone. Haste, on the other hand, haste is boring. It's watching paint dry. Maybe I exaggerate a little. In reality, haste is like watching paint dry <faster>. I'm sure at a certain point, paint can dry fast enough to be entertaining, but I don't imagine getting enough haste to see that happen. You see, I play a warrior. All of my single-target rotational abilities either have no CD or have a reset proc. The only attack I use regularly with a CD is my AoE/Debuff. I gain nothing from melee swings. Haste, as such, is an especially boring stat and would require a complete rebuilding of my preferred spec to be anything approaching useful and more interesting than avoidance.