That comment was solely aimed at the typical composite wings we see in GA and sailplanes where things like skin stability (can) drive the weight, much more, or even surpassing the influence of the spar weight as seen by monocoque sparless wings like that of the Diana II (the lightest wing in it's class). Of course, in an airliner, the wing is basically nothing more than a heavy beam, with lots of things (flaps, slats, engines) connected and my comments aren't valid there.I posted pieces on the SoarIdaho website (dealing with Schreder sailplane designs) some years ago on this well known concept --I described the wing planform as of "Eiffel tower' shape as an easily visualized analogy -- the wing outline can be concave rather than convex as for an ellipse but the straighttapered or compound tapered wing comes close enough .
Most jetliners have such a planform --more apparent if you unsweep them --and gain a great deal of strength and weight saving ,fuel volume and landing gear stowage etc as well . I disagreed with Autoreply that spar mass is almost neglectable in calculating wing weight and that skin weight is dominant (on another thread on HBA) --and this planform concept is the physical embodiment of the primacy of bending material mass . (there are a couple of other reasons for adopting the "Eiffel tower' shape in swept wings --eg the Horten flying wings -- the 'lift deficit' in the centre section being one --an effect of the isobars sweep and spanwise flow , also possible thinning and decamber of the root intersection ).