What you observe to be a "yolk" I observe to be the embryo inside the seed coat. The Pokedex might refer to them as eggs, however it makes a lot more sense if they are in fact seeds (or fruits, in which case the "yolk" or "embryo" is the seed itself) due to Exeggutor resembling a coconut tree. Besides, it wouldn't be the first time GameFreak has used layman's terms (esp. in the Pokedex) to simplify concepts. There are several analogies between (fertilized) eggs and seeds.
Regardless, I still stand by my assumption that many people disapprove of Pokemon based solely on human made objects or food items. Despite Pokemon botching the concept of evolution from its inception, at least the Pokemon were still fit to survive in their environment. I can't imagine a situation in which it would pay to be accidentally eaten by a unaware child with a sweet tooth.