I agree, it removes metal from behind the cutting edge.

If you are comparing to a single bevel then that is true. But if you
are comparing to a primary/secondary bevel method then it depends how
you do it. Hollow grinding followed by flat honing like Krenov
recommends seems like better geometry in my investigation. Link below.

--------------------------------------------------------------------------------------------------------
What I've learned about sharpening plane blades
http://members.shaw.ca/petermichaux/...harpening.html