Some people like me will justify it due to being a huge hobby for them. It takes the place of what other people would spend going out often, traveling, streaming, etc...

I've got a rack that pulls ~600W 24/7 but that's across 4 machines, 3 UPS's, >30 HDD's yielding >20TB across multiple zpools, >256GB RAM. And I'm actually using most of that capacity, not just idling away.

I do hope to upgrade soon to power-sipping platforms like you mention but currently I'm still on R710/R810 stuff (Westmere Xeon's).