[atleastoptimal]

True. If humans didn't have a positivity bias our own intelligence would be unbearable. We have to be able to viscerally imagine and reckon with the worst possible realities while keeping our heads above water. It's also why I believe humor exists: it provides a psychological and social reward for effectively navigating negative circumstances.

[vacuity]

I think that people tend to mix emotion and reason too readily. To an extent we are governed by our emotions, but we shouldn't let them consume us. Negativity bias is definitely detrimental but so is positivity bias. That's different from being compassionate. Compassion is a principle, a moral axiom that many people hold, but positivity bias is saying we should feel blindly feel good. We should have a tempered view of our principles and personalities.

Your explanation of humor seems woefully inadequate. What is the corresponding solution to a negative solution in making a dad joke?