This is a little inappropriate and I'm not putting it out there to offend people, it's just the truth and the reason people make fun of toxic "NA DOTA": anyone who thinks Brazilians / Peruvians / Russians are the "worst teammates" has never played 5k+ DOTA on the weekends.

Random east-coast college kids have become my absolute bane, I go from lovely weekday matches with pretty friendly / communicative teammates who tend to work together, come up with a plan and want to win the game... to raging college kids who want to play 24-7 "spawn-gank-die" DOTA and wind up feeding horribly after the 30 minute mark when the enemy starts to 5-man.

I think the reason is that "weekenders" just want to make big play DOTA and have every game be 5 kills a minute... they don't have any grasp of the importance of item timings, push windows, "fighting when your lineup is strongest", etc.

Eh, sorry, enough whining - I too cannot stand "casual Saturday" DOTA. I just had a game where I took safelane PA - indicated it, asked teammates to pick appropriately... and they decided to do Ember mid with an aggro offlane tri built around Slark. I begged them not to do that because we'd have zero teamfight utility and would lose the game on the highground push. I calmly explained how easy it would be to counter-pick us and punish that all of our sources of physical damage would have difficulty in long engagements.

They didn't listen, we lost horribly after the 35 minute mark, just a predictable, completely avoidable loss created in the draft stage because a weekend player wanted to do an aggro tri offlane with his friends instead of playing the game "properly". I don't rage, I just "ggwp" and move on - but it's definitely irritating that my time is wasted.

TL;DR - a lot of weekend players have zero "RTS" game sense and draft / play stupidly, causing losses.