[Walt.]

In what way is waving at dozens (hundreds?) of total strangers a sign that a person is happy or friendly or anything at all? Why would anybody care one-way-or-another if this total stranger waves back? Is there some sort of quota we're supposed to meet?
By the same token you could say that the cashiers at "Subway" or "Dollar Tree" are really friendly because they say "Welcome to..." whenever you walk in.
It's as impersonal and empty as your 4,000th "friend" on Facebook.
Hard to believe this sort of topic keeps coming up.