In fact, Bitcoin does not consume so much energy for its production as compared to our other types of activity, in particular, for example, for the work of banks.
Banks service several billion people. Bitcoin serves maybe 5-10 million on a regular basis. That's one angle that doesn't stack up in the slightest.
Excess or waste power is pretty much the only leg it has to stand on to fend off accusations of profligacy. Other than that it's a fact and a distasteful one and I don't see how it can be defended no matter what desperate leaps of logic are attempted. Best we can hope for is that the user numbers catch up to match expenditure of power.