I didn't discover upright cycling until I hurt my lower back from helping a friend move (blessing in a disguise, I guessed). I got my wife a Dutch bike because she got into an accident and I thought upright riding is safer than riding in a aggressive posture. Since then, we both enjoy cycling more because we can just wear whatever we feel like and even without helmets on short journeys. The less hassle the easier to bike. Notice the Dutch bikes all have attached locks. With all the obstacles that we have to face everyday like shady neighborhoods, noise and air pollution, and poor road infrastructure, so having to not worry about putting on gears helps.
I rode a 15 miles to work this past week for Bike to Work Day and I was the only one in a group of 25 with a Dutch-style bike. Everybody was surprised and asked me the exact question, "it must be comfortable, huh?". They were in gears, the whole outfit or clip-less pedals, helmets, and on road bikes. It's just too much to get anyone to cycle especially with women. They see it and get turned off.