It's no exploit. The enrage (if they even have one idk, never hit it), is negligible. It's a pretty smart strat to sacrifice the dps to get the tile buff out more easily. An exploit would be more like finding an area in the room or an action that prevents you from being eligible for chaining and then having people use that to their advantage. Blizzard knows tanks don't get it, they designed it that way. If they didn't want you to be able to do that they would have made it so only tanks with threat on something don't get chained.
Why would you? It's not even a tank dmg thing with one probably undergeared OT. I have mostly 463 gear, with a few DPS items and I can solo tank one just fine. I'm not sure why you would 4 tank it -_-
The 2 other tanks aren't tanking anything, they're using a tank spec because you don't get chained when using a prot/brewmaster/guardian spec, which allows two people (1 on 10man) to just run tiles for the entire fight without worrying about chains.
This also means 2 other people people in the raid (1 extra in 10m) are excluded from getting chains so that's slightly less movement restriction on the raid.
Additionally to having people running tiles all the way up to 150+ without a worry in the world it means people that are chained that would normally be forced to move off the boss in pairs and awkwardly try running tiles no longer have to worry about it so overall dps on the boss skyrockets.
Whether you want to call it a bug or clever use of game mechanics, it turns a reasonably solid heroic fight into a complete walkover.
Last edited by Thisisanalt; 2012-11-14 at 11:53 PM.