Sure the games you listed are classics but only within pinball circles. If you're trying to reach a larger audience, a license does that easily. For example, look at how many sites not associated with pinball ran a story on the new Ghostbusters machine. A license makes the publicity and sales easy and the gameplay secondary.

I like the way Spooky started with a non license at a limited run. It helped to get there foot in the door and now they're on to game three. I think if Stern would have treated Whoa Nelly as a limited run, they would have sold much faster.

It's amazing how many people will buy something when it's a limited edition.

Stern has proven that it doesn't need to be fun to sell machines. They've sold a ton of machines in the past based on the license and when the game came out with lackluster code, no one for sure knew if the game would get any better. It seems only recently that Stern has taken an initiative to update code on older games and ship new games with more complete code.