Hmm, agreed and disagreed. As much as I hate to quote Ip Man, he did say "the bong sao never forms", and that's pretty much an integral point most WC people miss - if used as a transition, bong can be very effective. Just don't stick it. I've actually used bong/lap chop somewhat effectively from a dominated position in the mount (admittedly against mediocre grapplers) Positioning of the rear guard hand is paramount with the bong as well. Between the sternum and forearm and halfway between the hand and elbow.
I don't know, I've used it effectively in a few situations and am quite happy with it. Another thing bong does fantastically - elbows. In fact, that's about the only SD application of it IMO. Everybody these days thinks they can flatten anyone out with an elbow... uh-uh sunshine