I think you have a more nuanced and reasonable definition of positive thinking than most people — and that’s key I think. It’s not about being positive or negative as much as it’s about having a mindset that allows for setbacks and rationality.
I think our only difference is semantics more than anything else. Resilience is one I prefer drastically to positive thinking, because there are a majority of people I know have that oversimplified, rudimentary definition. No, it’s not black and white but too often it’s interpreted as such. Neither is negative thinking and being prepared for the worst possible scenario.
We have a drive towards being positive and I just don’t know if that’s the most encouraging thing to say to someone who just lost their job or just lost a loved one. Semantics might be trivial, but they matter a lot to people. To me, the most effective thing to say to someone going through a rough time is “it’s alright to feel this way. Let it out,” while being there for them while they move on.