In the developed world in particular, we're seeing the move away from fossil-fuel power. This is good but currently relatively expensive.
Crypto mining is starting to have very real impact on the ability of other people to live. It is adversely and disproportionately affecting poor people (who pay a greater share of their income for power).
And at best crypto provides extremely limited utility for society.
Crypto-mining apologists will point to figures that say "crypto-mining uses mostly renewable energy". What this actually means is that crypto-mining is focused on areas that have hydroelectric power because it's the cheapest, generally.
While you might say that's still good, it's starting to raise prices for other people. this has been an issue in towns on the Hudson Valley in New York, for example.
Even if you believe the overall impact of crypto-mining is small I guarantee you it's only a matter of time before politicians start using crypto-mining as a convenient whipping boy.