Commuting shoes can widely vary depending on you commute. My commute is 16 miles each way, all roads, no walking. I use my road bike, and my road bike shoes for that. I have seperate shoes and clip on my MTB. My tri bike had road pedals on it, and I use my road bike shoes.

If you want a shoe that you can walk around in all day, and then jump on your bike, yes, MTB shoes and SPD style clips are going to be better. If you change your shoes after your ride, work all day, and then change back, then road shoes and clips will probably be better.