Why do people give up at the slightest resistance?

I had a KOTH game the other day that I have been thinking about. We won the first point. On the second point, we had a hard time. The enemy team had made some swaps. What we were doing wasn't working. Our Moira flipped out in chat and wanted us to deathball (our comp was not made for this and the enemies was made specifically for this). Anyway, they were frustrated, tilted, and had all but given up. Then round 3 happens and we win. So we won overall. But we did it with a teammate who was pouting the whole time. They had completely given up. I don't understand why people do that instead of focusing on what could be done differently. For example, this Moira could have gone Ana to help with the Mauga or the JPC. They didn't do that. They didn't look at anything they could do differently. They just complained. I don't get it. It ended up being a close match.