It's awesome, but it should get even more awesome as BTC gains mainstream acceptance. The energy usage should hopefully one day match that of the USA or at least India to be even more secure.

After all, if Bitcoin is going to become the global reserve currency a 51% attack should be absolutely impossible. Right now all the mining being done is rewarded with a measly ~$55 million per day. That's within the reach of some rich individuals to outspend, to say nothing of big businesses, hedge funds, or even nation states. I think spending about $1B a day on mining would be more appropriate in the long run.