It's things like this that make you stop PuGging. I absolutely will not step into an instance with people I don't know anymore. When I get tells from people looking for a tank for the daily heroic, I make up an excuse unless I am guilded with or have been guilded with/have known that person. And if the rest of the group ends up being people I don't know, I'll bail at the slightest provocation. Rude to me? I'm gone. Racist? Bye. Homophobic? I left my oven on. Bad loot behavior, looting in combat, rushing pulls? I have something else I could be doing.
There are plenty of good players in the trenches trying to get through a heroic who I would be happy to tank for, if there wasn't always at least one guy who makes it an unendurable nightmare. The hunter who does less damage than the tank and freaks out once damage meters are posted. Oh yes, and it was this same hunter who demanded that they be posted. Or the fury warrior who keeps taunting mobs off of the bear tank and then wondering why he dies every pull. Let's not forget that guy. The guy who rolls on every plate drop in the instance even if it's tanking gear, even if it has +spell damage or +healing, totally ignoring the ret pally who has stated up front that he intends to respec prot and is trying to put together a tanking set. The warlock who takes an epic BoE healing cloak and equips it right there on the run.
I know you've had these experiences too, the problem for me (and a lot of other tanks I've talked with about it) is that the toxicity that these experiences engender seems to linger in the tanking mind. Perhaps it's because PuG's usually seem to expect me to lead the run, making me some sort of nanny when loot bs or other personality issues comes into play. Maybe it's just the stress of tanking and then seeing someone like Primula outroll me on a piece of tanking gear that is basically the only thing on the run I would even want. I wouldn't say that tanking is harder than DPSing, but it's stressful in a different way because, like a healer, you feel like the entire run is on your shoulders and that everyone is watching you the whole time. Compounding that issue with groups that make the experience unpleasant just isn't worth a tanks limited play time.
When I tank, I tank for people I know won't treat me poorly, and so unfortunately that leaves a lot of perfectly good players I haven't met yet looking for a tank. Yes, there are greedy tanks, bad tanks, and tanks with unpleasant personalities, but the fact is that every single class in the game can come to a run and DPS. Only three of them can come tank. Every single DPS class has more than one DPS spec, but the three tanking classes have one tanking spec and two other specs (two DPS specs for warriors, a DPS spec and a Healing spec for paladins, and even more variety for druids) and so, not every member of the three classes that can tank can tank him or herself. There are less tanks to start with, so even though you only need one, you notice when no one wants to do it. I assume it's much the same for healers, but since I don't heal as much anymore I won't make a claim.
I hope Primula enjoys that new PvP trinket, especially as one poster pointed out, when she drops below 35% health standing next to an arms warrior with a Stormherald. That 2k overpower crit is brought to you by the Commendation of Kael'thas.