I suppose that art style is guided by the complicatios of having some nice solutions to the realistic texturing problems. It would be impossible to support a realistic texturing for every kind of creatures that are being made. The only solution in these kind of situations is to go way with the cartoonish texturing as it does not shows any flaws and falls nicely into the modelling design chosen for spore.

And the whole thing is attracting all kind of people towards itself. I doubt that such a thing can be implemented in A7. LOL.