My guild so far has been one of the better "We're more casual than some, but more serious than most but we get shit done." We raid twice a week for 3 hrs each, which is considerably less than any raiding schedule in my past. We have a decent core set, but the real meat of our raiding crew can pull out some phenomenal shit to get things done, and we still have the few people who kinda scrape by or just don't care. We didn't get the "Silence is Golden" achieve on Atramedes until we did him without our ret paladin, because he constantly just sat in "for his dps", even though we would specifically say, hey, fucking stop it.
Some people if you even attempt to say anything will give you something along the lines of "Well, I don't play this game to min/max, I play to have fun." Which is all well and good, but in every guild I've been in, I have only been in it to get shit done, and that was the reason I joined. So, if you're in that guild, and the idea is that everyone should be playing at a certain level, how do you come off half cocked to anyone?
I was in a top teir guild in vanilla; we were number one on our server but merely amongst the pack of good raiders serverwide. However, that was still a far cry from most. After AQ40 we were burned out, and joined a friends guild on a pvp server. It's interesting, that both JTheRuler and ZProtoss highlighted things that I myself have felt - when we moved, they were a guild trying to progress in AQ40 and were serious about doing so. I was playing a healer at the time, but my old main had been a dps class. There were things people were doing that were just blatantly wrong for any number of reasons; strats that were wrong because they weren't coming from a reliable source, dps classes who weren't following rotations, and didn't know shit all about their class. This is all fine if that's the type of guild you're in. But when you start going off about how awesome you are, and how leet the guild is, and woo progression, but then can't take criticism, it's crazy. And I couldn't say anything, because I was new, and it was my friend's guild and I didn't want to make waves.
Eventually however, they hit a wall on progression because they weren't doing the things most guilds do to progress through 40 mans. Their strats were flawed, and they weren't willing to keep banging the encounter out, or make changes to do it correctly. And the collective dps was terrible. Not a damned dps knew their rotation, or things like normalized speeds on weapons etc. We're talking elementary shit about classes that you should know. I did pipe up a few times and was instantly branded as a bitch and know it all, so I shut up.
So I see it both ways. If the guild is working and doing it's thing to it's level, and someone new comes along and wants you to change all your shit, well..that won't happen. But it's an entirely different thing to be failing spectacularly, and have someone point it out, in a nice way, and be told you're an asshole because you want to help.
And this is interesting because I agree it's something I really only see in wow. Most other genres you can really only play one way, whereas MMOs have a sense of casual, and hardcore, etc, etc, meaning someone always has a reason for why they suck and why they don't care if they suck. And that's not really an issue until you're expected to meet a specific level of play, otherwise you are wasting everyone else's time.