Actually, unless you are dealing with someone who's over-the-top ignorant, even the die-hard Harley fans will acknowledge other cycle brands. At worst this just leads into sub-classing of the Motorcycle / Biker group. If I showed up to a 1% rally (not bloody likely in the first place) on my Venture, I can expect that it would probably wind up vandalized, but so long as I showed proper "respect" to the members of the head MC, no harm would necessarily come to me personally.
There's also the other bit. It doesn't matter the style or brand you're loyal to or what you say about riders of other brands/styles, if you're riding an open 2 or 3 wheeler, be it scoot, bike, or trike, you're part of the biggest club on the road. You'll be acknowledged by other riders on the road and it's courtesy to acknowledge other riders in kind. If you come onto a road behind a squad of bikes, regardless of your ride, members of the squad will signal of road hazards to you as they see them; and you're free to part ways at any point and you're likely to be waved off in a measure of good wishes.