I should have been more clear....I don't commute on my bike... from a commute perspective I wouldn't be too eager to say hello to every Jane and Joe on a bike.
I cycle on weekends and after work on farm roads and the only cyclists I see are out training. Given my circumstances I wave or nod and I feel its appropriate.
Gotcha. Still not something I've ever felt comfortable with.
Several years ago I attended a family reunion on the in-law side in Kamloops, BC. A smallish town where everyone says hello to you. IT DROVE ME INSANE! Here I was, trying to have a nice quiet walk and enjoy the landscape, and every minute or so someone would interrupt my solitude. Felt like being slapped, it was that jarring!
There are spaces where social interaction is expected and desired... to me roads, sidewalk, pathways, etc. are not among those spaces. Then again I don't get why anyone would cycle in a group, so what the heck do I know?