I guess I don't understand what the big deal is. I always assume the tank will pull big and prepare for it, if they stop then I simply extend my DPS duration.

In the event of a wipe... who cares? Are wipes and a a overzealous loud player really worth worrying about?
I would like to think that it doesn't matter a lick.

Fact of the matter is, if you have a tank that is even remotely geared to pull large, your going to be healing a large pull. Whether or not it's the tank's or the healer's fault is really irrelevant. If the tank is competant then a large pull in the current dungeon structure isn't anything to worry about. We, as players, have to operate on the assumption that in DF people have a reasonable understanding of their job. If we do not then we will simply not use DF or we will become those players that this post has spawned from.