Isn't it by design? The Bitcoin difficulty move depending on the mining power, thus lowering or increasing the cost of operating a miner. If it's unsustainable, then miners will go out, the mining power will decrease and it will cheaper again.
I guess an outside force (private corporation or government) can try to leverage that as a weakness by injecting capital into their own mining operation, thus making it unsustainable for miner to operate and then getting the majority but that would be a whole other story (and we would still have ways to mitigate it).
There could also be some kind of critical point where too many miners keep doing it unsustainably, in hope to survive longer than others and stay up (but that would be absurd, they could just start it up again later when it will be sustainable again, but humans are humans...). They all close at a similar point and the difficulty stay way too high and it's literally too expensive to reach the next difficulty change. Even then, we could try to inject cash at that point or developpers may force a difficulty change... but it may be too expensive and we abandon Bitcoin because of that.
>There could also be some kind of critical point where too many miners keep doing it unsustainably, in hope to survive longer than others and stay up (but that would be absurd, they could just start it up again later when it will be sustainable again, but humans are humans...).
This is not absurd at all, most miners have a lot of sunken capital as well as ongoing costs such as fixed term rent and electricity contracts they cannot easily get out of, thus many continue to operate at a loss just in case price improves over time. A lot of traditional businesses also follow this model.
I guess an outside force (private corporation or government) can try to leverage that as a weakness by injecting capital into their own mining operation, thus making it unsustainable for miner to operate and then getting the majority but that would be a whole other story (and we would still have ways to mitigate it).
There could also be some kind of critical point where too many miners keep doing it unsustainably, in hope to survive longer than others and stay up (but that would be absurd, they could just start it up again later when it will be sustainable again, but humans are humans...). They all close at a similar point and the difficulty stay way too high and it's literally too expensive to reach the next difficulty change. Even then, we could try to inject cash at that point or developpers may force a difficulty change... but it may be too expensive and we abandon Bitcoin because of that.