All of this occured this afternoon. The experience cost me several braincells and I may just have to relearn the English language. Every group was in a row.
Stratholme Attempt #1
Pandaren Brewmaster tank (shocking). Starts going decent enough. Then the tank starts to grind to a halt, claims he doesn't want to tank because he thinks he'll die too much. Asks his friend (same guild) to change. We wipe once on trash after the abomination grinds us into fine dirt due to mobs swarming the healer. Tank blames it on lag.
Reach the Tobacco Boss. The tank runs ahead whilst we're still fighting mobs to try and 'steal' his quest item, unawares that opening the crate spawns the boss. Spends the next ten or so seconds looking straight at the crate for his item whilst the boss (the adds still alive) devours the healer and DPS. Blames it on lag despite numerous movements to the contrary.
Stratholme Attempt #2
Mage starts shouting "Clearfastclearfastclearfast" which is a good sign of things to come. Tank DCs infront of Abomination trash, Rogue quits, group wipes due to sudden appearance of several dozen ghouls. Group disbands.
Stratholme Attempt #3
Group goes for The Unforgiven instead (fair enough). Tank quits half-way through killing trash despite no prior issues. Tank joins after emptied trash, but by then the Rogue quits. Begin moving on boss before the Tank quits again for apparently no reason. Group soon follows.
Stratholme Attempt #4
Starts off well enough. Reach the Scarlet Bastion when the tank leaves the instance (see: not quit) and tries to join for Blackrock Depths instead. Spams the invitation. Nobody accepts. Group disbands due to waiting for tank.
Stratholme Attempt #5
Tank tries to go fast, ends up pulling Abomination and additional ghoul trash. Dies in roughly three seconds. It should be noted that he actually has less HP than the healer. Group (surprisingly) continues regardless, though the healer gets the blame despite the tank being the one ignoring aggro. Rogue rushes ahead and gets killed by trash, spams "resmmememresmemeresme" despite us trying to finish off the trash he aggro'ed and thus still in combat. Wipe in the library/pillar room prior to the Cannon room due to the tank deciding it would be a good idea to try and break the line of sight of the healer.
Rogue begins to ninja loot every drop. Reach the final boss. Killed. Entire group bar two try to ninja loot and instantly leave without a word.
TL;DR - HNNNNNNGGGGHHHHHHHHHH.
Good lord, this was horrible. I normally don't bother with using the Dungeon Finder bar certain dungeons I hit during my world levelling experience. Needless to say I will be avoiding them entirely up until I hit Pandaria. Inb4 "omg y u qqing" passive aggressive remarks, etc.
Anyway, I'm interested in seeing what other horror stories people have of their group experiences. Please don't turn this into a "Dungeon Finder ruined WoW" argument, since this is for schadenfreude more than anything.