Bolt would pull right through the hole in the strap first time you stomp on the pedals. I'm not sure how you can see that as an improvement.

There are many parts of the design that lend themselves better to low-impact hybrid and recumbent riders. They were marketed to the MTB scene for quite a while before SPDs took hold. If you ride 'em hard you'll be replacing them on a frequent interval or duct taping the hell out of 'em.