Originally Posted by
tjspiel
A first question should be along the lines of "How long is your commute one way and is it relatively flat or hilly?".
Absolutely, as well as asking whether the person is a fair weather commuter, or all weather commuter, and a daylight commuter or all lighting conditions commuter.
Also, perhaps there are interests in other cycling activities.
There is no one-size-fits-all.
A smooth tire MTB may be fine for a 2 mile commute, but I certainly wouldn't suggest it for those riding 10+ miles.