They do not care about the environment. Bitcoin contributes a lot to global warming by design.
Plus, Bitcoin is a valuable asset (for many people) and the reason it keeps its value is that it's safe. Energy is expended to keep it safe. That is a free market choice, and you can disagree with it, but many choose to pay for energy to protect Bitcoin.
The free market needs to be controlled when it destroys the environment. The people needs to be responsible for their actions.