@Vocenoctum:

I can understand how you feel. Being an quite experienced and good player, you're having problems with the fact you are unable to go to Naxx because you're also a guildless and casual player who doesn't know the fights. That's frustrating.

However, "If raiding together, every mistake you make costs other people time, money, and causes a little stress too. You can laugh them off, but they do have consequences. A middling league football or baseball team that picks up a brand new player who does nothing but drop the ball will quickly run out of patience, and it's the same in raiding. Even people with the gentlest temperaments and best intentions can get frustrated when they are constantly corpserunning due to your mistakes." is entirely true and the reason you're not getting a group. Most experienced raiders have seen the stuff described by Jennie happening a lot and they are tired with it. Naxx is a very fun instance, but it will take at least 3 hours to complete and even longer with an inexperienced group (and remember that an inexperienced group means wiping a few times, which also costs a lot of gold).

However, as you're annoyed you can't get a group for Naxx, i conclude you do want to run Naxx and thus have the time to do it. It will be a lot easier to get a group if you can say "i haven't done it before, but i'm skilled, i have the gear and i know the tactics". Obviously you have the skills and the gear, you only don't know the tactics. Some excellent Naxx-guides were written in Readycheck (i think it were 5 articles, written in dec 2008 - jan 2009). It takes some time to read through them, but not as much as a Naxxramas run. Read them and you're ready for your first Naxx-run in no-time ;-)