Teaching cursive is at bottom just a way or regularizing and making legible what people do anyway when they get faster and better at writing by hand. See Fraggle's post. But it is not taught that way - it is taught to children too young to need it, as an essentially useless adornment or "accomplishment"; probably a holdover from when the ability to write was a class distinction. So it seems like something that could be discarded without loss. My guess is that most people don't write by hand enough to get much benefit from taking the time to practice it, and so if times have changed enough to eliminate the class distinction then no problem.