Not necessarily, it may have been an advantage at a point when the african environment or climate was different or when there were different predators and prey. Things may have changed leaving an opening for the gene of the "normals" we see today and the spider gene may have not been needed any longer. There just isnt enough factors known about ball python morphs in the wild. Maybe in the particular region where alot of spiders are found there is a predator that is detered by the wobble assuming that the snake is ill or maybe there is a type of prey in that region that that the spider gene has specifically adapted to in order to catch. Too many unknowns.