There was an article just the other day of a coal plant that was entirely restarted for PoW coin mining. PoW systems are
not proven to incentivize renewable energy R&D and investment. There's no proven link there. There's no proof that a PoW coin ban would "kill a major driving force of change for the better". Sure, a restriction on carbon output
would be such a driving force, but there is no such restriction today and it is wishful thinking to believe that PoW miners are following anything like one in a market where such externalities continue to be unregulated.
It is orthogonal to the issue at hand that PoW is using far too much energy per transaction/per capita/per GDP/per most metrics you want to point to. Not using the energy in the first place is always going to be greener, no matter how much PoW systems invest in renewables and their R&D! I can't see that as "misguided". An outright ban would get immediate results versus a carbon output tax would incentivize eventual results, maybe. That's not misguided, that's just a different perspective, and a different preference on an ideal time window to address the situation versus wishful thinking and "golly gee, sure hope the market eventually figures it out someday".