I consider myself a "hardcore motorcyclist" ( I own 4 bikes and for the last 17 years commuted 125 miles a day even throughout single digit temps ) and I personally don't consider the Slingshot to be in the bike category. But that wouldn't stop me from waving at one if I'm on a bike.
Having said that, I think pretty much all the bikers out there do drool over the Slingshots and I've seen a lot of their (female) passengers just stare at it as we pass and I can just imagine her saying "Honey, can we get one of those?" lol