Agreed. I actually considered that exchange when typing the former message, but were we to consider a serious overpopulation problem, such as, let's say... 20 billion mouths to feed, then perhaps technology for identifying humans contaminated and/or spontaneously developing prion mutations that'd lead to TSEs, would become a top R&D priority.
The taboo on cannibalism seems to stem from transmissible diseases associated with it, but I can't help but wonder how many humans on earth would be required to turn a fully-developed human body into a resource unfit for "mere" ritual disposal, rather than recycling. And yeah, this sounds awfully dystopic.
Fiction and speculation aside (which doesn't seem to imply we're dealing in the realm of the sane), I'm afraid this is PETA we're talking about. Those were the guys that sent a letter to an ice cream producer requesting them to consider using human breast milk rather than dairy products on their ice cream. It really wouldn't surprise me if they went as far as calling for the introduction of human meat in supermarkets.
I'd suggest using humans as plant fertilizer instead, but whenever I ssay that, people seem to have problems with it.