Yeah, it's a strange thread, but it is doing some good to flesh out psychologies and (perhaps) myths.
After amassing a reasonably large sample set of interactions with hikers, dog-walkers, hunters (less so), and the like, I've whittled and whittled my part in the interactions to where I'm now comfortable with many of them passing silently. If the situation merits, I may smile, wave, speak or even stop to talk, but I recognize that it's not necessary for us to like each other, or even deal with each other, aside from showing respect in sharing the trail. If they're cool, I reciprocate. If they're not, I show a non-threatening, slightly disinterested visage, and keep moving.
Again (with regard to the original post), fellow travellers -- of whatever stripe -- are free to speak and behave as they please (including making funny faces) right up to where they're in my space. Until then, I keep peace with all.
Both Giggy and Gris may have accurate analyses.
With no disrespect,
--M.