The only explanation I ever heard that made sense to me (the "official" one from B&H does NOT make sense and just to be blunt, I don't believe it) is that B&H is so huge, and their shipping department so correspondingly large, that it's cost prohibitive to train everyone in the needed hazmat procedures, or to separate out such shipments into a smaller sub group. That makes sense to me, and if they said that I'd say "ok, I get it, I'll need to order such items from smaller companies but I understand." But that stuff about it not being allowed after ValueJet seems to me to be nonsense. Too many other places are readily willing to ship the same items, advertise that they do so, and are not getting shut down or in any kind of trouble at all.