I'm all for being a contrarian, but let it go. When someone says "commuter bike" you instantly get an image in your head and it isn't of your Dura Ace Equipped, Titanium, Seven. Yes, you're free to commute on whatever you like and it may even work better for you than a "commuter bike".

The fact is that "commuter" is a category of bike that is manufactured just as "racing bike" and "touring bike" are categories. That's not to say those bikes are only good at those tasks or that you must have those bikes to perform those tasks. Sheesh.