Joe, you'd have to ask Howard that. d;^)
Lemonwood was probably so popular because it was so available, uniform and cheap. I imagine in its hayday lemonwood was used by everyone, even the top guys.
Hugh, osage is a dense, hard wood but as a bowyer I don't find it all that difficult to use. I actually like the fact that it fights back as you are building a bow. It gives it more spunk when all is said and done. Also, osage manipulated better,IMO, than other bow woods so even not so perfect pieces of osage can be wrastled into a bow with a little heat and work.