Unfortuntely difficulty regulation works in completely the opposite direction. This is because it is in the interest of the dominant competitors to invest in hash rate; not to improve the block resolution speed but, to make mining so darn expensive that only their cartel is left with exclusive access to the mining pool. When eventually the difficulty decreases as other players drop from the mining game, the cartel-of-actors is left controlling the difficulty.
Perhaps if we make the mining do something useful outside the blockchain, such as medical research or hosting content, we could effectively "trick" the cartel into doing something useful. I don't think cancer patients would care if the research that's helping to heal them was done by millions of individuals or a few data centers.
"take advantage of it or it takes advantage of you" is just waffle to justify behaviour which isn't quite up to snuff. It's like taking 20 packs of sugar because otherwise the restaurants is taking advantage of you, or selling power to your neighbours using extension cords. Functioning adults shouldn't need to be told that's frowned upon. Besides, most home owners will also include a fair use policy or allow domestic use of their property and amenities only.
Solar power is far from free. It takes quite a few years to break even. $150 a month is what a kid with a paper route makes. That's hardly a business venture, especially if you're doing it on someone else's dime.
Did you miss the part where the rent for places that include electricity is a lot higher than for similar properties that do not include electricity? Something like $200/month extra when for similar apartments in that area, $100/month for electricity is already on the high side. It would be a different matter if it was just $80/month extra where everyone is expected to conserve to keep it that low. In reality, if mining crypto is bad, so should be refusing to turn off the HVAC or at least reducing its use when leaving home. (I think the latter is what those schemes are marketed towards.)
If you don't have net metering, then sizing your solar setup is a tradeoff between covering more summer/winter usage and not being able to get good utilization during spring/fall. Crypto mining using cheap hardware during spring/fall is one way to boost utilization. I suppose you could keep it small so there won't be much surplus, except solar panels often get cheaper as you buy more at once.
The way you refuse $150/month sounds like you're the type who refuses to own a garden because you can buy fruit and vegetables for cheap at the local grocery store. Fine, you're helping to keep the difficulty from rising as fast. Or actually calculate how much you make compared to the few minutes you spend per day maintaining it and it turns out to be a decent rate. (Good luck delivering the papers while only using a few minutes per day or less!)
Solar power isn't free, but how much do you really think you need to run 7 mobile devices? Figure a 100 kW solar farm oughta do it? Nah better make it 200.
I get the temptation to make up ridiculous scenarios that nobody in their right mind would actually try to implement, but it's not really informative. Assuming our cyrpto-mining enthusiast has enough money to set up a real operation then yeah, you could pay off the solar panels reasonably quickly. Assuming you don't live in Norway or something.
Whether it's a total waste of energy is another topic but hey, at least it's renewable energy!
A single 100W panel was all it took to power my mining setup at that time, with some left over to run other stuff.