The whole point of a dealership hosting any type of event is to get people thru the doors and asses on the seats of bikes. They wanna sell bikes, parts, and merch...... They don't care how you arrive whether it's 2 or 4 2"wheels long as you leave $$$ with them as you go out.
Because none of those car owners or people who showed up to look at those cars would perhaps wander inside and buy some stuff from the dealer, like heaven forbid a new bike, or at least a Tshirt or lowly poker chip?
Good way to get some new traffic in the door, if you ask me.
Same dealer had a gunshow back Memorial Day weekend I sold a gun there. I also have bought bikes from them in the past. Right now I am a little miffed that they took 2 weeks to fix my trans. (warranty) but I will get over it or not...
My local dealer has a car show a couple times a year (jeeps one time, corvettes another, etc.). Seems to pull in a lot of traffic (yeah, yuck, yuck). I happen to like cars as well as bikes, so it gets me there.
Hot Rods and Harleys every Thursday night at Chattahochee HD in Columbus, GA. I never go, but I think it also helps meet the budget for the event. By getting more people out they can have beer and food vendors and make more of an event out of it. Otherwise, it's a 5-10 Harley dudes standing around looking at each other.