I can barely ride in regular clothes or regular shoes. I did a few times when I had my flat bar road bike, but my butt hurt and my feet slipped off of the pedals on just a 3 mile ride to town. I do try to ride in more "commuter type" clothes when I do errands, but I always have a cycling liner under my pants or shorts and cycling sandals or shoes on.
Perhaps if I had an upright bike, no hills, and no propensity for sweating, I would.