On reflection, I don't really mind bad players too much as a whole. I mean, it's annoying as shit to have a terrible brainless team, but that's just internal saltiness and you can easily resolve it by leaving when the match ends.
Apart from people who rage over voice comms, there's only one set that I truly despise: the CoD players. You know them. You've had them. The people who, regardless of context, never pick anything but offensive heroes. Not because they're situation-appropriate. Not because that's their best hero. Because they want to screw off, ignore the objective, and chase kills. Those fuckers are worse than people who pick Widowmaker on King of the Hill matches.
That said, I think Blizzard had someone with a real head on their shoulders doing a lot of the planning. The lack of any sort of stats screen is an unspeakable godsend since it cuts out 90% of the sources of stupid bullshit fights and flaming in both MOBAs and FPSes. The fact that assists are treated as functionally equivalent to kills in every sense except the kill feed also means that there's even less incentive for people to just try to do the deeps and secure kills instead of playing properly. Objective points, blocked damage, and healing actually being equitable with kill points in both the end-game tally and exp gain is great. Which is why it's so mystifying to me that there are still morons playing like it's in any sense better to lonewolf and chase kills. I've had matches on defense where half the team pulled offense champions after the first point got rolled, and I could see their doritos floating out near the enemy spawn while we desperately tried to win a 3v5 on the point. o.0