I did call him an asshole and for good reason. Just because pubs are filled with misery doesn't mean you have to add to it. That's the problem with the vast majority of this genre's playerbase. Nobody realizes that, wait for it... You're playing with 9 other real humans. Behind that 300 gold antimage is a tired office worker who's had a long day and just wants to unwind, and instead is getting all of his farm stolen by what he though was his support.
I'm not contesting that you're successful at playing the game. I'm saying you're making other people suffer and wasting hours of their time because you want to have slightly more fun at their expense. That's not okay. Really, really not okay. All of that fun you have sapped by russians or brs or whatever? You're exactly the same. Just because you think you get to be a huge dick to your teammates because you win more doesn't mean your teammates do.
+1
Besides, I've seen that there a lot of people very cooperative while in-game, a lot of times they are just really bad/new to the game and their builds follow the in-game guides (most of which are aimed at carrying).
The thing is, while Dota 2 is definitely fun if you play by yourself, it's meant to be played with a team. It is much more enjoyable when played with a group of people you regularly play with, be it a clan or guild; because you can find out what works, what doesn't, and is after that that the roles appear.
What I normally do if I have to play with random people is get at least one friend and either we choose a combo (such as puck-lifestealer) or we are the supports for the rest of the team (who always play to be carry). Dota is a party game.