Originally Posted by Chris R.

Are you the type of person who can turn your neck regularly to check for cars/danger? (no sarcasm). I have never felt the need for a mirror of any sort but I am vigilant when riding on certain roads to check behind me often, just like in a car or on a motorcycle.
Some people don;t have the flexibility or may stray from their intended path when they turn around. In those cases a mirror may be a good idea.
Yes, they look a little silly but better than looking dead.