So we should have slightly depressed people in charge of projects and ruling the world, but optimists doing the work for 'progress' because optimism fulfills itself (obviously restricted to the possible, not that optimists seem to bother themselves with that factor.)
The problem being our company and government hierarchies vet extreme narcissists, who tend to be especially reckless and overly optimistic and small/single-minded.
It has occurred me, the world being the horrible place that it is, that 'normal' optimistic people can not be realistic or cautious given the necessary overcompensation to remain happy and optimistic, and that those who don't suffer from an extreme chemical imbalance but are nonetheless depressed would be more likely to make accurate predictions. The problem is that people (especially 'normals') pan things that make them sad, in favor of things that incite their anger or happiness. And depressed people kill themselves while the mostly unregulated, high, self-selecting birthrate assures the primacy of the reckless 80%. One more reason to actively re-engineer our species.
_Disclaimer: I don't hate optimistic people. I do think the tyranny of the mindset's majority is what must be overcome or re-leveraged to prevent catastrophic failure of our modern world. _