(It wasn't even solar or wind or nuclear that killed coal. Really, it was _gas_; the writing was on the wall for the industry some time ago.)
There is no longer the "voters don't want to lose their jobs" argument. Now it becomes purely a "these guys pay lots of taxes" argument - but with most big companies being very efficient at tax planning, a huge mine might pay next to no taxes too. Then it becomes politically far easier to ignore them, and eventually maybe shut them down on a whim, eg. to appease green voters.
There was once a time the conservative movement was built on pragmatic rationalism, and people keep looking for it in modern rhetoric. But it’s become built on fallacious populism recently as a short term way to grab power, then overwhelm the system to “rig” it towards their favored people. It’s not about conservatives or liberals, ideology or political goals are the foil. The goal is the appropriation of power and the blocking of democratic change in favor of cronyism.
So there’s no point in trying to find a rational explanation for the policy. There is none in the policy itself. It only exists to garner enough votes to do what’s happening in real time with the goal that with enough shenanigans voting won’t matter next time.