As a cyclist the main reason I treat stop signs as yield signs is because the bicycle tips over if I come to a complete stop. The physics are really optimized to keep going. Clipless pedals really force you to make a decision -- am I going to stop, or am I going to coast through. Maybe this is a poor design for a world where stop signs exist, but that's how it is.

(As an aside, for all of these bridges with instructions like "cyclists dismount", I think we should make car drivers do the same thing. Put in neutral and push it. It's for your own safety!)