Why is it when you're cruising along the trail and encounter another trail user, you say "Hi" and get NOTHING in return? There is no one else around, so I couldn't possibly be saying hi to anyone else. It is nature, so there are birds chirping, wind whistling through the trees, but it isn't loud enough to drown out my loud voice, so what is it? Do I stink? Do I scare you? I swear, all I want to do is say hi. I didn't fart and if I did, I wouldn't try to slow you down enough to partake in it (maybe I should start...). I am not going to tackle you, hurt you or heck, even have a complete conversation with you, I am just acknowledging you're there and I hope you're seeing I'm here.
To be fair, it isn't everyone and some areas of the country are better than others (the Front Range of Colorado is bad, just an FYI). I promise, I won't say anything to you when you are in the middle of a gnarly, oxygen debt climb, or at least won't expect anything out of you. But, if you can say hi, you should. We're both out on the trail together...we have that in common.