Normally, I'm a bit more level-headed than this with regards to the Dungeon Finder "community". Normally, I disagree with common gripes that DF pugs don't know their arse from a hole in the ground. Today is not normal. Today, I actually got a group with three DPS, all of which were contributing less than nothing.
Behold, the dungeon queue is over! Your long and torturous 3-minute healer queue has completed! Zoning in... what's this? An in-progress Zul'gurub? That's not too rare. Throw some buffs, drink up, ok, let's roll.
Hmm. 1.1M damage taken on a single trash mob? I'm amazed no one died. At least the melee had the sense to run out of the poison breath, although using the cauldrons (or, the Light forbid, standing behind the mob >.>) would have been easier.
So we get to Venoxis. Someone hasn't done it before, and the fight is explained summarily: spread out, don't stand in the bad stuff, and if you get linked to someone, run away. A single tick of the maze wall will kill you. Shouldn't be too bad; the other three know what they're doing.
The pull. Tank's taking negligible damage, the ranged have spread out... Hmm, a full-duration Whispers of Hethiss on the hunter. Frigging melee. I charge up a heal for him and... he's dead? What? A hunter corpse can be seen lying under one of the maze walls. *sigh*
Looking up, I see the tank run out of a poison breath. Good, good... bad. The DPS warrior didn't. I actually got a heal on him in time, and he still dropped. From full. *sigh*
So it's just me and the mage. Bloodvenom goes out, and (surprise!) dead mage. By this point, the boss is at 80%, and both the tank and I are still on track for the achievement. *sigh*
We continue fighting alone, and my mana is stable, we could probably kill it after about 6 more phases. I call for the DPS to run back in. They arrive much later, when the boss is around 40%. I notice none of them could be assed to eat something or bandage themselves. Well, whatever. At least we'll burn away another 10% of the boss before they all die again. Whee, the cavalry is here!
Turns out, it wasn't the cavalry. They pulled the fucking turtle. And instead of dying and learning from it, (or, you know, dropping aggro) they dragged it to us in the hope that we might save them. There is a giant fucking turtle the size of the entire room meleeing the tank for 50k in a fight where being able to see the floor is more crucial than key-binding your spells.
We wiped on 35%.
We would have been more likely to complete the fight with just me and the tank than with the three DPS in our group.
When performance is less than zero.