In really Bitcoin's power consumption is ~500 MW as of 3 months ago, which is less than the amount of electricity spent on decorative Christmas lights in the US: http://blog.zorinaq.com/bitcoin-electricity-consumption/
Also, Christmas lights can use a lot of power. Your example reminds me of those electric heater ads that say their product uses as much power as a coffee maker.
More popularity will lead to higher bitcoin prices, and that will indirectly to more power consumption for hashing until no-arbitrage equilibrium is restored.
It is still increasing at a rate that would make most startups jealous when they look at their own growth rate: https://blockchain.info/charts/n-transactions?timespan=2year...
"If it ever becomes popular for more than crime and tax evasion, that's as lot of Christmas lights."
It's already more popular than that. Bitcoin is no longer driven principally by "sin" activities: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2808762 And see the nice growth in various areas: https://en.m.wikipedia.org/wiki/History_of_bitcoin#Growth