Sorry but this reeks of nonsense to me. Even if true, surely the compute power could be used for protein folding or something actually useful instead of hashing bits only to throw the results away the majority of the time. Crypto needs to die.
Not all cryptocurrencies require a ton of electricity. Some, such as those based on Proof of Stake are extremely efficient and use very little electricity so it's not fair to disparage them all on that basis.