In Texas and California chaparral country cowboys who worked as "brush poppers" would often wear leather for protection for branches and thorns. Protection just like motorcycle jackets. I can't say I've worn leather for protection when scrambling around on rocky slopes and such but I've been occasionally happy I had it on!
I think Filson's 15-oz. oil finish Tin Cloth works the same way for hunters and outdoorsmen as protection against potential damage from the briar patches. I think their mid-weight Shelter Cloth and to a lesser extent their lightweight Cover Cloth, as well.