If murder of a minority group was legalized and someone decided to murder their innocent neighbors and steal their stuff to make a buck, would all of the responsibility really fall on the legislator and none on the murderer?
Imo an immoral act stays immoral whether or not it's encouraged or discouraged by the government or social environment. I find it somewhat more understandable how people can carry out something cruel if it's legal and completely normalized, but "It's not their fault" is much more apologetic than I'm comfortable with. Especially when they make millions off the suffering and deaths of other people (due to inadequate medical care).
Machine learning has some genuinely good use cases though. Protein folding is probably the most useful for society yet, especially for medicine research. LLMs can at least save a lot of tedious work, depending on the task, if used responsibly.
Regarding fossil fuels, it really depends on the use. For new electrity production, residential heating and cars for example it's usually not needed anymore, and just a massive waste of carbon budget. For other stuff, the alternatives still have a long way to go to become practical.