moshimonster, welcome to the forum, btw. 🙂
This comes up a lot on here.
Waving at some roadies is fraught with risk, as it reminds them that they’re just people who ride bikes, like the rest of us.
Those currently taking the piss are probably the same miserable cyclists who don’t wave at people.
Let them get on with their insular little lives and keep smiling and waving.
That annoys them even more.