I'm a frequent player of Avatar and MUD's in general for quite some time. I have alts on pretty much all the major MUD's in the list of the top ten.
Comparatively, I'd say Avatar deserves a better reputation than those that attack it, give it. Every time I need help on the game, it's given to me. I tend to be a low mort player. ;) Pretty much meaning I don't spend a terrible amount of time in the game, I just play an hour or so from day to day. It's good fun. The Immortals help you out (say when you're drowning and no one else can). The Immortals tend to listen and have a bit of fun. I remember awhile back when Crom was an Imm, he spent a lot of time chatting with the players.
The players are also very helpful. All you need to do is chat something and you'll get five responses to the question and then those that answered will argue about that it's their newb to answer to. :) That's what I like about the place, people are helpful. If you need some help getting to your corpse because you accidently teleported into a high Hero area and the uber mob smashed your brains out, the heroes will go in and fight the uber mob. It's great fun that way.
Also the ability of the immortals to come up with such a comprehensive MUD School and Help archive is very impressive. One thing that puts me off of some MUDs is that you walk in and all of the sudden you are fighting some crazed lunatic before you know it, you're dead. Avatar's MUD School first introduces you to MUDing in general, then it goes for Avatar specific stuff. It's very new-player-friendly.
Although, the MUD has a few drawbacks (like all games do). I find it difficult to group when I'm on. Mainly because there's not a tanker on whilst I play. Though I still try to group with other hitters and we die, but it's all in good fun.
This was a weird review 'cause I just typed what came to mind...anyway, if you're looking for a good MUD Avatar is the one. Good people, friendly and helpful. BTW if you think the people are degrading you for not knowing the mud, they're probably just joking. Some people can't read sarcasm online very well.