For me the difference between fixed and freewheel is greater than the different between geared and single speed. When I started to ride a fixed gear it was almost like I was learning how to pedal all over again. I remember cresting that first big hill and then *trying* to coast.

My son uses BMX pedals on his fixed gear and so do lots of his friends. He's definitely a fair weather rider though and isn't making many mountain descents on his. He also insisted on removing his rear brake so like many teenagers safety isn't his first priority.

Again, I don't consider foot retention an absolute necessity on a fixed gear but I do consider it safer than regular platforms, - along with having other advantages.

To put it simply: Safety isn't a reason I'd choose clipless pedals on a geared bike, but it is a reason for choosing clipless (or other method of foot retention) on a fixed gear.