I have noticed the same results about waving and friendliness as reported here. More roadies nod or wave to me since I got my Kuota; for God's sake i had a Trek 5200 before, so what's the deal with that? I'm always wearing cycling clothes, too. I see the same people a lot on my after work rides. Now I know which ones to nod to and which ones wave. The commuters never wave...
People on hybrids or recreational riders seem shocked when I say hi. A funny story relating to this is for years we saw a guy running on the streets in our old neighborhood as we rode. We called him the "mean" guy. He never smiled or waved, said hi when you said hi to him. My son made it a "thing" to get this guy to talk back to him as he rode by. Finally, he got some response back, after like 2 years. About 2 years after that we found out it was Bill Rodgers, the 5 time winner of the Boston Marathon! He lived about half a mile from us. He got nicer when he had some injury and was walking instead of running...