Shhh. Remember how in the classic thread half the posts were people making lame veiled insults to each other (not outright flaming of course!)? I guess they're just staying in that spirit.
Just don't go too overboard or we're done... but I didn't have to say that.
To answer your question, there's a stereotype of the gaming clan as a bunch of kids with huge egos who spend more time trash talking and making excuses than actually winning battles. You've maybe seen the type... crappy website, spamming join requests, long incomprehensible (or unintentionally funny) clan tags, weird rules, ugly colors, etc. Getting into online fights with other clans arguing over who can beat up whom, accusing each other of cheating, etc. Or clans whose only goal in life is to amass as many names on a list as possible, with no regard to skill or coordination.
That's the negative image, I didn't say it was true of everyone, but it's certainly a well known stereotype, at least it was to me! Look at virtually any site making fun of clans and you'll find it!