I did a turn on the roadbike today – couple of hours hard riding up in the hills but a bit more urban on the way back. When I wasn't close to spewing my lunch up, I gave nods, "hi's" and jaunty waves to roadies, mtbers and so on (couldn't move for bl*dy cyclists today 🙂 ) and got it back in turn – from the lot of 'em.
There were however, a couple of times – usually when I was piling down hill, trying to avoid potholes, eyes streaming and both hands to the bars, where I wasn't able to look right, let alone wave at oncoming cyclists.
I apologise for being ignorant. It wasn't deliberate. Maybe the same applied to the guys in question?