Basic skills in bike repair/maintenance are sorely lacking. They've never learned to replace an inner tube, never really wanted to learn for the most part, and especially in this age of cell phones, they see making a phone call to arrange a pick up as the preferable way to deal with a flat tire. Work in a bike shop for a while, and you'll be amazed at the lengths folks will go to in order to avoid fixing a flat themselves.

Personally, I've seen the ability to do on-the-road repairs as a part of riding a bicycle since I was a kid. Crap happens, you gotta be prepared. Currently, I carry one or two extra tubes, tire lever(s), inflation device (pump or Co2 depending on the bike), small patch kit, basic multi-tool w/chain tool, and a chain connector link on all of my bikes on all of my rides.