Devil's Workshop?

At my place I constantly harp on energy conservation and related issues -"Switch the lights off, Sonny". "Turn down the water flow, my dear maid". "Let's take the bus today for a change", and so on.
My husband is good-humouredly tolerant of all my strictures, but I just got a glimpse of what he thinks of this habit of mine.
This morning he donned helmet to take the two-wheeler to work, and I was surprised…he usually prefers more wheels, a hood on top,... “I am glad you are finally getting around to thinking green…”, I said. To which his reply started thus: “An idealistic mind is a devil's workshop….”