It was just for fun. Part of my job at the time was evaluating benchmarks, so things like the water simulation were on my mind. I don't remember if there were microwaves on each floor that I might have used instead.
I don't dog-ear book pages, if that makes you feel any better.
Reminds me of the Wired bitcoin miner[0]. They bought an early ASIC miner and used it to heat coffee on a livestream.
[0] http://www.wired.com/2013/05/butterfly_live/
(also I dog ear pages so we're even)
I'm not sure why this is like nails on a chalkboard for me. Maybe it's the programmer equivalent of dog-earing book pages.