PoW is throwing away electricity for the sake of it, and resists getting more efficient. If the goal is for the bitcoin network to cost $1M to do a single double spend, then PoW has to use $1M worth of electricity every 10 minutes.
Let's say we live in a future where we suddenly have 10x as much electricity. Due to supply and demand, electricity now costs 10% of what it did before.
Dryers etc all keep using the same amount of electricity with no issue, but bitcoin has a problem: it's now really cheap to double spend unless bitcoin uses 10x as much electricity. So of course, it does.
There's a similar proper with making things more efficient. If we make a christmas light more efficient (make it use an LED instead of an incandescent bulb or whatever), christmas lights will use less electricity.
If we make ASICs or GPUs more efficient, then people will just have to run more of them, or else bitcoin will be less secure.
I think this is a real and notable difference, and I think that's enough of a justification to consider a ban.