While motorized bikes don't do it for me, I have no problem with them being in the build off as long as the bike is also pedal powered. They have been allowed for years. I don't see the need to have a separate class for such a small subset of the builds. Traditionally, there have only been one and more recently two classes. Splitting the build off further into various sub-classes doesn't make sense in my opinion. Unofficial sub-classes have been loosely organized in the past with mixed success. I don't see the need to have separate categories, Klunker, Strandie, Motor, Stretch, Lowrider, Boardtracker, Roadie, Muscle, Chopper, BMX, etc......... Just build a cool bike and have fun.
My opinion on watering down the build offs with a ton of classes hasn't changed from above. If we add enough classes then everyone can get a prize . Oh wait, that has always been the case!!! The only guaranteed prize that every single builder gets is the one that they build and ride with pride down the road.