This started as a reply to this good post and kind of grew to be only slightly related, so I'm making it its own post.
a few years ago someone made me notice the "hidden constraints" people have for solving problems and how most of the time we don't even notice they're there until someone points them out.
This was in the context of climate change: solving climate change is complicated only of you have the hidden constraint of "nobody should lose money about it." You know how we get to stay under a 1,5°C increase in global temperature? We stop using fossil fuels. That's so complicated! Except it isn't. We fucking shut down the production/extraction of fossil fuels effective now, and stop nonessential production/transportation while we create and move over to a renewable infrastructure. But then some companies (and governments) will lose a bunch of money, do you know how expensive that would be? So instead we have all these "commitments" from companies to reduce carbon emissions at some point in the future and "international treaties" with "targets" for member countries to stay under so we can all gradually, so gradually, move away from fossil fuels without losing anyone any money. Too bad none of this shit works, we're still on track to break a 2°C increase in the next decade. It's just so complicated to stop using fossil fuels (without losing anyone any money).
Of course these hidden constraints apply to other things as well, not just environmental stuff. Money is the most common hidden constraint, though.
Homelessness is such a complicated issue to solve. Except it's very simple: you give people homes. We can't just do that, though. Because it costs money.
And this hidden constraint ends up lodging itself in people's brains so deeply that it's still there when talking about hypotheticals or alternatives for the current system. I was discussing with someone if widespread air filtration in public buildings downtown could have a measurable impact on air quality outside, and their reply was that it would not be cost-effective.
Ah, but I wasn't wondering if it would be cost-effective. I was wondering if, were all pubic buildings downtown fitted with high-quality indoor air filtration systems, would the air immediately outside them show a lower concentration of particulate as well.
That hidden constraint is still there when thinking about alternative systems. Oh, sure fully automated luxury gay space communism sounds great, but how are we going to pay for it?
Money is not the only hidden constraint, just the most common one. "How do we keep the Undesirables from using/benefitting from this thing?" is another common one. "How do I make zero changes to my lifestyle while changing the system?" is a third one. Related to that one is "how can we change this system without disrupting it or going outside of it at all?"
Of course, there's others. And none of us are immune to this shit, so we should all be asking ourselves, frequently, "is this actually complicated or is there a hidden constraint that makes it so?" "What implicit requirements do I have for a solution to this problem that's making me ignore actually viable possibilities?"