Every single thrower I encounter is on an alt account

Yet somehow they aren’t a problem because they ‘calibrate quickly’…

I think there needs to be some clarification on the official developer stance between throwing/tanking, boosting, and owning alternate accounts.

Source: https://us.battle.net/forums/en/overwatch/topic/20753717332?page=24#post-475

Furthermore:

That being said, if a player, regardless of their skill rating or experience level, is ever deliberately throwing the match, report them. But if they are just playing badly, use CAREFUL judgement and its best to assume a low-experienced player is in fact a low-experienced player.