I interpreted it as meaning that optimism is an assumption that problems will go away so there’s no need to painfully face them, whereas pessimism is an assumption that things will get worse unless you actively search out problems and fix them.
Pessimism is the thought that it cannot be fixed and it is hopeless. Optimism is wishful thinking and avoidance. You want to aim for realism.
ah yeah, I mean if that's the case, I think that's orthogonal, right?
In my interpretation of the words, I tend to think of optimism as being the brave thing because having hope is more difficult, and IME, you can only muster energy to solve a problem if hope exists. Conversely, pessimism to me feels cheap and easy, and if you say "everything's fucked, what's the point" then nothing gets solved
So, it's probably more of a quadrant/compass along the axes of optimism/pessimism and proactive/passive