Hmm. Very good point from PilotDAR there - rather a personal bias in my viewpoint; almost all the aircraft I fly are G-meter equipped, I mostly fly aeros, consequently have a decent G tolerance, and was thinking of things like a roll and pull through, etc. There's no earthly reason to be pushing VNE on a spin recovery I agree.
I'm still interested to know if I'm missing something on Genghis's point however. For the tapering of the Vg plot, I'd always assumed it was simply that you're putting a whole load of stress on the spar in the rearward sense, leaving it less capacity in the vertical sense - the loading upon it being vector sum, rather than neatly resolved parallel and perpendicular. Quite probably more complicated than that.