The orginal reason wing bungies were designed was to allow fast deflation in restricted/overhead environments (cave diving). The secondary BC was and is the dry suite for dives of this nature; thus, no need for oral inflation. Bungied wings were never intended for recreational diving, without dry suites.
Having said that, while I have US Diver rigs for recreational diving (Wings without bungy), I often prefer my Dive-Rite tech rigs with bungy for those dives as well. I disagree with the arugment that bungy compressed wings do not improve streamlining. I have discovered that in dives of long distance, especially against mild currents, there is a reasonable reduction in resistance with bungy compressed wings. When diving bungy wings without dry suite, I use dual-bladder wings (built in back-up) with dual inflation hoses, so the "manual" fill is not an issue. However, the additional hose adds one more aspect of complexity and can potentially reduce streamlining if not well stowed. I do agree that trying to manually inflate bungied wings is a challenge..so I avoid it.
Net-Net: Bungy wings are for trained and prepared technical divers. What they offer in streamlining (unless dual-bladder, dual inflator) to a recreational diver without dry suite, they take away in risk.