You might be consistently impressed, lately I have been consistently disappointed by the Dota 2 community.
Sometimes you get teams of mature people who realize we're all in it to have fun, who will wait for you, crack jokes while you're all waiting, and generally make you feel better about the game. Those have been some of the best matches I've played, and included extending condolences to the other player when I've killed them and giving them tips on what they could do better after they respawn.
Other times, people will just yell at you, swear at you, call you names, constantly unpause the games, and just be horrible shits.
Also, I wonder what's different (culturally) about Russians, as they seem to be, by far, the less courteous of the bunch. I think they are racist towards Americans, so when someone speaks English, they basically go "fuck him, he's an American". A few of my friends go the opposite racism route, and say "fuck him, he's Russian", but I obviously try to tell them that you shouldn't be a dick to someone if he's not been a dick to you first.
Contrast this with any other multiplayer game and you'll see constant harassment, cheating, and an overwhelming lack of team play. Overall just too many people who make it their job to ruin the games.
The only thing I'd change is better onboarding of new players. There's a big gulf between the tutorials/bots and PvP. The first 5-10 real games for a new player are filled with insults, and losses.
Which is significantly annoying because there is a bug where you get disconnected from dota. Your only fix is to shut down steam, and I've had to turn off my modem and restart it.
And theres a 5 minute timer waiting to ban you if you are either AFK, or not earning EXP.
Then theres the bans for being a noob on top of that. As a result, its currently sub-par to on par with Dota 1 for me.