They're fine on a track bike, and arguably valid retro porn despite the challenging operating procedure. It's not as though there was a better option at the time.
Old films of crashes show riders locked to their bikes as they crash, because everyone used to tighten ther straps too much.
The M71 was not much more dangerous.
The Look pedal was popular because it released in crashes.
Slack chain.
Cinelli M71 pedalsofdeath.
Very ugly.
Fail.