Well, I post a lot and am ignored as much as KPaul (or whatever he is called now) is slammed, so here goes.
I've been riding longer than most of you all have been alive. Started with 'jap junk' when it was just that. Waved at everybody then, not many waved back. Got more than my share of ribbing by my Harley riding friends back then. Took it then and now as good natured ribbing. Moved over to Harleys before "they" started riding them, waved at everybody, most didn't wave back. Early on got flipped off more than anything by the riders of other brands. BMW folks just cooly ignored the wave. Then I added BMWs to my stable, again waved at everybody, few waved back...but the BMW crowd started waving...have continued riding Harleys and BMWs (currently between BMWs, but a tasty older one has been picked out as the next victim) and noticed more and more folks waving back, from cruisers and sport bikes. But the rhetoric between brands continues, the most vocal being from the non-riding wannabe crowd that can be and should be ignored. They usually get the loudest when drunk. Then I went and got weird and added a sidecar to one of my Harleys. Damn, everybody waves at that thing. Recently added an older Goldwing (that's right, Harley rider finally bought a Honda) my arm gets tired waving back at folks...
So the point to all of this? There are recalcitrant pricks out there regardless of what you ride. Don't make their anal reaction to your politeness change what you do or how you feel about motorcycling in general. Also, many cruiser riders lust after the speed and handling of the sport bike and the many sport bike riders lust after the comfort afforded by most cruisers. Basically, it is just a good natured mind game when folks slam other riders and their bikes. A patch holder a while back summed it up best, for me at least, by saying "I really don't give a rat's ass what you ride as long as it makes you happy. I ride what I ride just because it does make me happy". So, be happy, wave amd if they don't wave back, wave until the pricks go by or wave back...no need for you to be a prick becasue they are!
In other words, don't take the Cruiser Rider-Sport Rider crap to seriously. It is all in fun and, if they care to be honest, most of the sport bike crowd are going to end up on those bikes they revile because as you get older, you just don't bend as easy anymore...