Echo this. I was lucky enough to get into the closed beta a few weeks ago, when one of my friends sent me an invite key. There was no tutorial when I started (though there's one now), so I just went into a no stats game. The people there, and in most HoN games, seem to be just generally mean, elitist people who votekick at a moment's notice when another player doesn't exhibit some tidbit of knowledge that they're supposed to have acquired. This is really bad in HoN, since those votekicks affect your ability to play legitimate games. So, if you know a lot about DoTA, good game. Otherwise, stay away from it unless you know other people in meatspace that can help you out.
I want you to imagine yourself going down to a bustling inner-city basketball court, joining a competitive 5 vs.5 pick-up game, and then asking your teammates how to dribble. What do you think would happen? How do you think they would react? Now, imagine weeks/months later that you've gotten better. What is the appropriate response when other players start poking fun at you, talk trash, get fired-up, or act generally immature / politically-incorrect? If your answer is to never play basketball again, then you're really missing out...
Culture shock. The DOTA community is severely misunderstood. Though it may not be apparent to newcomers, Heroes of Newerth / DOTA is a very complex, dynamic game that heavily rewards quick reflexes, individual skill/knowledge, and teamwork. Matches are routinely won or lost by a split-second mistake of even a single skilled player. Conversely, a well-coordinated team will steamroll disorganized groups of individually superior players. In short, it is a game that demands a lot from players. The resulting community reflects this. They expect a lot from each other, and can be quite a prickly bunch. I liken the atmosphere to that of a sports locker room. As mean and fired-up as people can get, it's all in good fun. The best way to get someone off your back is to dish it back at them. Toughen up. (Yes, we know it's just a game. No... Nobody actually thinks that you have Downs Syndrome...)
What I often see leading to conflict and the aspect of the game that I see new players struggle with the most is that everything a player does--and DOESN'T do--matters. To be more concrete, take team communication for example. In most games, it is sufficient to just tell your teammates what you're doing--kudos if you tell them what you see the enemy doing as well. That doesn't work in DOTA; the map is too large and the battles too furious and quick for that. In other words, even exemplary communication skills for other games will get teammates killed, strengthen (i.e. "feed") the opposition, and potentially ruin the game. The only solution is for players to take their communications one step further by also letting their teammates know (within seconds) what the enemy ISN'T doing, most notably by "calling missing."
Once you understand the above, it becomes obvious why the DOTA community has the bad reputation that it does. Maybe some of that reputation is well-deserved, I don't know. What I can say for sure, though, is that once you get into it, it is a blast. No other game has captured my imagination, driven me further, and consistently offered something new like DOTA has. And I've been playing for years...
My advice: If you are considering playing HON or have just gotten started, don't let the first impressions of the community stop you.
P.S. If any of you noobs do decide to play HON, just don't feed and not call missing if you're on my team. K? ... =)