Thank you for indulging this because the opposition refines the idea. The objection I'm interpreting is that this will make the price of electricity in the region too high for anything else because of that demand. I'd say that in exchange for locating there, it provides a certain percentage of power at a loss rate, and this electricity supplied to the region is in effect a tax. Regional energy needs above a certain level would have to pay competitive prices for it.
If I have a hydroelectric dam or geothermal plant in a little remote mining town, and I put the output of whole thing towards miners for proof of work/waste/sacrificial block processing, that means the processors are taking something that is local there (hydro power) and refining it into value (blocks that facilitate economic transactions), and exports the value instantly via satellite uplink to the global economy (completed blocks, proofs, etc).
This means we don't have to transmit electricity hundreds of miles/km and lose it. We just refine electricity into compute processing, and export its service value as processed transactions right there. Since most of the renewable electricity is being used and isn't being transmitted, it doesn't effect broader energy market prices, and creates further incentives to innovate to optimize power use in the region.
I get the sense that most of the objections to cryptocurrencies are because the low bar to entry and decentralized nature makes them the wrong kind of Keynesianism, where instead of government printing money to pay hole diggers and hole fillers, we're using the same proof-of-waste algorithm, but on machines instead of people.
Speculators as a bugbear aren't a thing when you are building something either, so I'm not sure that's a material argument.