In a fight like H. Alys, tank DPS mattered, so standing in fire was completely logical. In 5s I do roughly 18-19K DPS as a tank and my output varies in raids. In general, the DK I tank with does more damage than I do and I was very happy to be within a couple K of him in DPS for H. Ultrax this week (first week was a 4K difference). But there are some specific gearing differences between DKs and Paladins (weapons, lol) that tip the scales in their favor (IMO).

I'd say that it's more fight specific than anything. Currently any tank swap fight that I start, my cotank has to either push a ton of output or I have to switch to auto-attacking (or walk away). I've zoned out and pulled a mob right off of him without thinking and then died because I wasn't aware of my own threat (threat is the first thing I forget about when I'm pissed or tired). Rag was ALSO a massive PITA for this and I regularly ended up walking away from the boss so I wouldn't pull him back and increase my stack count. It's just more of a headache in my mind than anything. I get what it was designed to do, but at a higher level, I would prefer it do what Theck has recommended.