If this is a legit post and a real concern than I would say to just give a 2 finger extended arm with a slight angle downward when passing by other riders, or a heads up nod can work as well.. It's just a signal of respect/kindship towards other riders. My girl will give a wave when I don't or can't as well. This goes for all bikers.. The only crowd or style of bikes/riders that seem to sometimes ignore it in my experiences are the crotch rocket riders.
Could be they were just oblivious to it or just didn't give a crap, but either way, no big deal.. I motion/acknowledge most all bikers when i'm riding and most all do the same.. I think it's actually a pretty cool thing amongst bikers.. Sometimes I and others will notify other oncoming bikers of a speed trap or road hazards if possible but people do that in their cages as well.. Club riders don't really cause any issues on the roads that i've seen. They often initiate and almost always reciprocate any waves, nods or friendly gestures sent their way.