I agree with the OP. Back in the day most club cyclists would wave to each other when passing and also wave to solitary riders not attached to a club but just out enjoying riding their bike. Hell, we'd even wave to middle-aged ladies cycling along on their hybrid with a wicker basket on the front - I guess as a mixture of encouragement and that we were kind of all doing the same activity. Two wheels good! Our club picked up a few new members doing this but things slowly started to change about 15 years ago and are getting progressively worse so that now most cyclists do not wave when passing. On my daily commute it's slightly better - perhaps 50/50. It gets right up my nose when you call out a cheery "Good Morning" and get nothing back except the thousand yard stare.