For many companies, converting a qualified lead into a closed sale requires the involvement of an actual human, and some degree of actual skill - which can only be acquired through training.
(Oddly enough, even automated systems need training.)
Let's be clear: Product training is NOT sales training. The former involves understanding features and benefits. The latter involves learning how to persuade a prospect to buy. Are those things even related???
Making matters worse is that there's a lot of bad sales training out there. But what do we know? We only make our living at it.