Because clean and efficient fossil fuel is code for removing investment in renewable technologies, and billions of dollars invested show significantly less return than the gains in renewable energy sources.
I don’t buy that this is an either/or situation. One example that comes to mind is the improvements in the efficiency of gasoline powered vehicles while electric vehicle production is ramping up. I think we’re better off that there was a huge push for making ICEs more efficient when electric vehicles were still in its infancy (I can’t prove this but I don’t think throwing more money at Tesla or other companies could have significantly sped up their timeline)
Renewables arent going to solve our increasing demand for energy and thus not really more important than to make oil cleaner and nuclear more popular. Renewables er themselves not as clean and certainly not as scaleable as nuclear.
Our demand for energy is NOT increasing, at least not in the US. Demand has flatlined since 2007 and more efficient appliances, bulbs, etc are to blame. I have TVA and they have been egregiously self-sabotaging their own solar program in all sorts of ways because the dang sun is a threat to their monopoly and would cut into their revenues. And renewables are so much cheaper, TVA has shifted $1.4 billion of their operating costs from large industrial to residential customers to further disincentivize their switch.