I understand your overall point of view, but it seems to me that certain things are getting mixed up a bit, particularly, usage level or frequency on the one hand, and implementation vehicle (to call it somehow) on the other.
Unless I'm missing something, Hecht would not be relevant in a scenario where 2 pieces of code are incorporated into a system, each in a different way (i.e., core and plugin) but used with the same frequency. Which leads me to the following point: what is more likely to be used more frequently in the WP environment: a core-feature that ships with WP or a plugin that you need to download separately?
That being said, I don't have anything against plugins in general, but we all know the huge problems and annoyances they tend to generate. I, for one, do think that core is more reliable, stable, and way better supported and documented than plugins, and I will always prefer a core feature over a plugin one. This is probably because I believe WP kicks ass and because I trust the people behind it. I would not be using it if it this was not the case, or if it was called "Plug Press", "U PLug", or anything similar (you get the gist).