I don't like to throw the term noob around that often. It carries a good degree of social stigma in the world of warcraft. Obviously, not everyone reads blogs, has a level capped character, raids, and has been playing since vanilla. Heck, some people don't know what we mean when we say vanilla. Still, there are some people who make comments so drastic, that you can't help but wonder where their mind is.
The first example came with me DPSing a Blood Furnace run on my mage. We had a couple warriors in the group, a mid 60's one who was prot, and a lower 60's one who was DPSing as well. The prot warrior was having problems holding multi-target aggro. I can understand that, I struggle with that on my Druid. It came out that the warrior was dual specc'd and did not use his prot spec much, he was primarily Fury. The other warrior then asked why he wasnt using a two handed weapon with a shield because as fury he could have titan's grip. For some reason he thought dual spec meant two specs at once and we couldn't explain to him what dual spec actually was. . .
The next example was also as DPS with my mage. We were running Hellfire Ramparts with a Shammy healing. I was the highest level character in the group. Our other members were a blood DK who was tanking, a ret pally, and a rogue. First of all, the group was saying how hard ramps was. I know it can be difficult if you're under geared, but if ramps is a problem, you're REALLY gonna have problems later in the game. Anyways, thats not the noob moment. The mace drops from the demon guy, I congratulate the RESTO SHAMMY. Then the DK says it's more of a paladin weapon. WTF!?!? Maybe if you're holy. He then proceeds to say all shammies want fist weapons cuz his buddy is a shammy and he does good DPS with fist weapons. Wow! I mean I'm not an expert theorycrafter but a ret pally doesn't want a 2h mace, a prot pally would want the shadowrend longblade (which already dropped and we gave to the rogue). That mace is one of the better early weapons for resto or elemental shammies!
The last example is more failtanking than noobness. I saw someone in general ask for a healer for UK. I have been burned too many times by crappy tanks, so I asked "who's tanking for you?". They said 80 warrior. Well, level 80 on a 70 dungeon, that should be a cakewalk right? Yeah, cakewalk for everyone but me. I died about 4 times during the run, at least we had no group wipes. On the last one I said in group chat "no offense man, but you're not holding aggro very well." His reply "I'm 10". My reply "I don't care how old you are, just stop letting me die!"
In summary, I don't like to throw around the term n00b, but sometimes it's unavoidable. I normally try to keep my opionions to myself (thats what blogs are for). It just seems like I have two talents in game: avoiding any kind of tanking drops on my main and attracting bad pugs on my alts (strangely most of the pugs on my main have been really good. . .I know it's not my UBER SKILLZ).