I don't want to inch us any closer to breaking into a John Lennon song, but I think it's important to think about the future in positive terms. We all have some power to shape our reality. Even if we don't all make a difference on a societal scale, we all influence our little sphere quite a bit. Hope and intentionality require us to "think ahead" and act with purpose. What is our country but the cumulative effect of all of our little spheres?
I agree, to a point.
The trick is knowing when it's time to accept that a trend has become unstoppable and it's time to get the hell out of Dodge, or to stop beating a dead horse before we end up dead too.
Hope untethered from physical reality is delusion, which IMO can be more dangerous than pessimism as it can blind us to genuine threats. That was the lesson I got from the cautionary tale of my friend's grandfather, who barely escaped the Nazis with his family. The rest of the family didn't believe things could get as bad as the crazy little man with the stupid little mustache was promising to make them until it was absolutely undeniable by anyone that he actually meant it (and the moment something gets so bad that no one can deny it tends to also be the moment when it's too late to do anything about whatever it is).
Grandpa and his family would have had a much easier time of it (and not lost nearly everything) had the rest of them been as willing as grandpa was to give up any hope of salvaging the nice lifestyle they'd grown accustomed to in Germany back when he did. Imagine if you have a popular and powerful neighbor and he writes a book titled I'm Going To Burn My Neighbor's House Down! It's like the difference between deciding to pack up and move your family to another state with the help of a big truck and some friends vs. being forced to flee outside in the middle of the night with only the clothes you and your family are wearing as your house goes up in flames a few years after your neighbor's book comes out.
Plan A ought to be to do whatever we can while we can to keep industrial civilization from imploding until we can render it sustainable since almost all of us will die within a month or so of an unrecoverable grid collapse, but history is full of examples where people were forced to go with Plan B if they wanted to survive. Which of course means that only those who had a "Plan B" and acted upon it actually survived (for the most part; sometimes a few individuals get really lucky). The catch there is that any such backup plans must be made and prepared for in advance of the disaster they are intended to address.
Hope and positivity are also relative. At some point "positive thinking" will shift from trying to save and protect what we have to trying to ensure that our species is not rendered extinct. And depending on what we end up facing in that regard, our survival could end up requiring a whole lot of thinking ahead and acting with purpose since it seems patently obvious to me that avoiding extinction among the few who survive a collapse will require a completely different approach to life and living than what's needed to prevent such a collapse in the first place.
So to learn and practice "Plan B" skills before they're needed is in my mind an example of thinking ahead and is motivated by hope, it just has a different focus (avoiding extinction) than hoping to keep what we currently have, which in any case is not really possible because a civilization based upon slave labor and over-exploitation of finite, nonrenewable resources is inherently unsustainable, and would be even if global warming didn't exist.