Well, look at it this way... When your hands are dry you put lotion on them, right? Now, right after you put lotion on your hands if you were to plunge them into a bag of flour what do you think would happen? Do you think there would be a difference if you used baby oil or just regular hand lotion? Would there be more than if your hands were dry? The level of oils in the lotion is going to attract more dust. Its also going to make your car pretty slick. You could cover your car with butter or Crisco and probably get a pretty slick surface. Its going to be muddy before too long, but it would be slick while it lasted.
Its just something that I worked out in my head and based it a little on what I've seen cars do. Products that left more oils on the surface after they were applied tended to attract dust faster than the ones that didn't have so many. That doesn't necessarily have anything to do with slickness though. You could use the slickest wax in the world but if your car is like sandpaper because of clearcoat failure and oxidation then its not going to be as slick as a freshly clayed car with no wax on it at all. Surface prep has a lot to do with the slickness.
I just put together that the more oils that are left on the surface will mean the surface is slicker. More oils means more dust too. Its just a theory that I haven't really tested. Testing which waxes leave more oils together and then feeling them for slickness would be interesting... It would depend on what you are looking for though. Is this going to be for long term slickness or fresh detail slickness? Is this going to be after 2 weeks or 6 weeks? Too many factors involved to really get specific.
I'm sleepy. When I get sleepy I get creative and think too much. lol Kinda like being drunk... I won't remember this post in the morning.

Disregard my ramblings if they are too crazy. I'm probably doing a lot of thinking out loud right now.
edit: I agree 100% that slickness is important. My question is just what is the cost of the slickness? People aren't allowed to touch my car anyway.

Cars collect dust and fingers dragging that dust just bug me. I don't care how slick the car is under the dust. Its supposed to be admired from a distance.

No touchy!