I guess this is for people who don't carry a wallet or who have medical issues like diabetes but don't already have a bracelet for that? For running or open water swimming I think it makes a lot of sense, but how many cyclists don't have room for a wallet in an underseat bag or a jersey pocket? I just don't see being written up as a John Doe unless medics can't find your ID in your belongings. I also don't understand how a velcro strap can cost $20.
But then again, maybe I should wear a bracelet to alert others of my cynicism.