So I vocalised into the mic, "oooookay... social... team chat... disconnect" as I did exactly that.
I proceeded to four-gold, and captured the first point nearly solo while everyone else but Sombra was trapped at spawn. (And, credit where it's due, Sombra definitely helped with the capture, mostly on the second third.) Yes, 1 to 2 on 4-6, depending upon how many could rush back at any given time to defend, and winning.
I can do a lot even for even a spectacularly shitty team when I'm on a roll - and I was.
Sadly, I couldn't capture the second point the same way, because the enemy were on to my tricks at that point, but, well, whatever. Four golds. I worked hard to make sure I had 'em all.
I then switched to Widowmaker on the flip side (defence) and popped in to team chat quietly for a second for a reaction, just in time to hear the same jackass bitching about everything, particularly the Widowmaker. And I popped back out.
We proceeded to lose, but I golded in objective kills and I think objective time but I'm not sure. (Might just have silvered.) As we're seeing all that, I pop back into team chat, and they're going at each other, just being salty as fuck.
So I hit my mic and say, "And this is why you don't call your four-gold 'retarded' - she might decide to play Widowmaker next round. Bye!" and dropped.
I realise this kind of snippery is not necessarily the best possible response to this kind of jackass? But I'm thinking, y'know, maybe he might be a little bit hesitant to let that shit fly right out the gate next time. Maybe. Because you really, really don't know who you might be playing with.
(For the record: I actually am trying to learn Widowmaker, that's why I'm playing her in quickplay a lot at the moment. Best kill streak with her so far is I think 12, max kills with her is 23, I've earned the Pixel spray but not the Cute. So if the team I'm with is any good, I'm not a joke, I'm a legitimate contributor, I often gold in objective kills with her, and I always play the best I can at any time. I always play to win. Even here.)