People enjoy unhappiness. It’s interesting. That’s why even comedies are about problems that need to be resolved.
So when coworkers get together outside of work, they complain. Focusing on mutual frustrations is more interesting than going on about successes. Everyone needs to blow off steam.
The candor that is possible outside of work is useful. It’s the tone that can be problematic. It can exaggerate problems and lead to the perception that the sky is falling.
The Fixed Mindset / Growth Mindset (by Carol Dweck) applies here. Saying, “We need to get better at X,” is entirely different from saying, “We’re terrible at X.” The former implies that the problem is a temporary state and the next step should be to fix it. The latter implies permanence.
Talking about opportunities to grow is exciting. Talking about permanent failures is discouraging.
If a customer were to overhear the conversation, would they say the coworkers are working on getting better, or wallowing in their struggles?