Whilst I think in general humans consume too much, a second dedicated commuter bike will mean you consume less in the long run - especially since it will mean if one bike is unridable for some reason, you've got a backup.
I've got an SUB of my own and was really afraid I'd get buyer's remorse ... instead, I ended up selling my car.


Since then, Trek's come out with a rather nifty Transport -- yes, the price tag challenges the "oh, get a beater and just ride it" -- but a well designed utilitarian bike really *is* useful and does the stuff that it's hard to do on a "regular" bike.