Look, people get mad when you are stupid in dota, new or old, having an uncharacteristically bad match it doesn't matter. The fact is a match goes about 40 minutes, and no one wants 40 minutes of fail due to someone messing up the game.
Protip:
If you suck don't join pro games
If you're a noob only play noob games, that's what they're for
If you're alright stay out of noob/pro games
Also everyone gets flamed as a noob, I'm sorry if you're too overly sensitive to take being mocked on the internet (which is some pretty serious business) maybe you shouldn't be playing dota in the first place
Less QQ moar P3w P3w