My therapist said to me once: "I really like pessimistic patients a lot more than overly optimistic ones. A depressed, pessimistic person is judging the world very accurately and is not crushed by a negative outcome, as they have already thought about exactly that. They might even completely circumvent the negative outcome, because they thought about every possibility beforehand. Optimists on the other hand can be cr…
Absolutely not. I've dealt with a lot of pessimistic, depressed people--I've been clinically depressed, as well, in the past--, and we can be the most closed-minded, whiny, oblivious people out there. I think that's exactly how depression actually works: one is enslaved, kept away from experiencing the world as it is, by their extraordinarily reduced perspective, which is seemingly unescapable to the depressed individual.
I don't think it's reasonable to conflate negativity--which leads to bad outcomes--with a realistic mindset--which takes into account potential bad outcomes. I find the opposite to be true, in my experience: the more positive and proactive a person is, the stronger they can become--and not crushed by a negative turn of events.