Let's Hear it for the LFG tool!

... or against.
Okay... it's not necessarily the tool itself I have come to detest, but rather a fairly large portion of those using it and taking advantage of some of it's "features."

Here are some of the more annoying occurrences I've witnessed using the LFG tool and the reasons why they occur:

Estelle - average ilvl 343 - holy priest
First, and the impetus behind this post:
queue time: 15 minutes / bosses down: 1 / Group make-up: bear, warlock, and 2 mages(all from the same guild), and me
Neither of the mages put up a table. I mean, really, how hard is it?
On each pull, one mage polymorphed one mob and the bear tank tried to pick up the other 4 mobs, but was unable to establish threat over the dps, all of whom took damage from various unmarked mobs. The tank died on 1 pull because he bit off more than he could chew (and I was busy keeping the mages from dying, figuring he'd use a cooldown if he got low or something), but other than that, nobody died despite their careless overconfidence. The boss fight went fine - didn't even dip below 80% mana. But right after the boss fight, they all dropped group.
You see... you can leave a group after a boss dies without getting a dungeon cooldown debuff, then you can immediately requeue. So people who are either trying to obtain a specific item or grinding rep can kill the most beneficial part of the dungeon then bail, leaving the person or people who actually waited in the queue without getting their valor badges - even if their performance was close to, if not absolutely, perfect. So yay for tanks and those grouped with them! They don't have to give a shit about wasting other people's time!

A couple of days ago, I joined the random queue and got Shadowfang Keep with another guild group from another server. Everything was going smoothly until the first boss, on which we wiped. Apparently, they wanted to do the achievement for that boss without bothering to tell me (the healer). I just assumed they were going to let the boss's heal tick on us once, so I wasn't panickly trying to heal people up after the asphixiation (which knocks everyone in the group down to 1 HP). Nevertheless, I had a lightwell up and a POM on the tank. My chakra had fallen off, so I didn't have chastise immediately available. Given the otherwise lack of instant heals, I cast Circle of Healing on the tank and immediately thereafter started a flash heal (1.3 second cast). The tank was dead before the Flash heal went off and obviously it went down from there. They proceeded to blame me in not-so-diplomatic phrase. This went on for about 5 minutes after which I simply asked them when their kick timers were up so they could remove me from the group (i wasn't going to leave and get a dungeon cooldown because they're inconsiderate assholes).
Solution: All they had to do was tell me before the encounter that they were doing the achievement and things would have run smoothly, but blindsiding me with it in combat then pissing and moaning about how much I suck was just way more fun (fyi - not 1 of them used any helpful sustaining abilities (hello.... cooldowns?) or clicked on the lightwell). I agree COH wasn't the most ideal spell to cast, but if I had known what they were doing, they would have gotten more than a knee-jerk reaction from me.