You answered your own question. Crank HP is fictional coz in reality its not what you get. As you've identified, losses can be many and varied. Motorcycle (and other vehicle) manufacturers like to quote crank numbers.... coz they're more impressive, but they're fairly meaningless when attempting to compare one bike's stats against another's.
^^ What koko64 said.
Well, for the sake of arguing... When you build a motor for a vehicle, do you test the ENGINE for proper HP output, or do you put the whole car together then dyno it to make sure the CAR is making the right power?
When you transplant a motor from one vehicle to another, do you use crank HP or do you use RWHP from a totally different car? I am using this reference because the same motor is used in many different cars but maintains the same HP rating, however the drive train is completely different. Think about the V8 ford uses in the Econoline and F150. Same motor different drive train.
And when you add non engine mods to the bike, you can only "Free up" hp. So if you bolted on a bunch of stuff, ligth weight wheels blah blah blah, you know you can never actually make your M1100EVO a 100hp bike because its 100hp crank, which means thats the max output of the motor. The average car joe knows that rwhp has about 15-20% lost. so u just multiply and subtract. But going the other way around, u have to set up a mini equation which is annoying to do. 15% of what = my RWHP?
I know all this stuff is just mumble jumble cause in reality all you want to know is how much useable power your getting when your putting it down on the road. but i dont think crank HP is a fictional bs number at all. it would be great if they advertise both.
And for the record my 1000DS puts 82rwhp.