Quote Originally Posted by Kish View Post
Maybe. Maybe it requires a BAB of +15 and so when Horace died without any of a tiny number of really high-level adventurers learning it from him, it all but died out. Maybe it can only be learned by a single-classed fighter (or, for more consistency with existing mechanics, has Greater Weapon Specialization as a prerequisite*) and so most people who might have learned it one day went, "Fighter level eleven is dumb level. Thog not take."

*This does run into the warblade problem, but still, if you need 12 fighter levels or 14 warblade levels to learn it, that's a tiny group of potential students in a world where very few characters ever make it to level 10.
Maybe it also has a high int requirement. Greater Weapon Specialization, Int of 16+, and some other flavor tax feat nobody wants, combined, would exclude most people.