Steel toes would likely be unnecessarily stiff and heavy for riding. I've heard the crushing steel stories too, but I've always thought if the horse stepped on your foot hard enough to crush the steel toe, that was likely enough force to crush a couple little bones to dust easily.
Those were going to be bad injuries either way, and the steel absorbed some of the impact.


“It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so.”                                                                                                                           ~Mark Twain