Well, I don't really know much about low poly, but I think if you are restricted to lower poly numbers, you will be forced to be efficient and precise and poorly constructed meshes won't let you use each poly in the best spot, if that makes any sense.

If you're free to throw a ton of polys around, you'll be more likely to have a sloppy mesh... I guess it's analogous to... well I can't really think of anything at the moment, but if you learn low poly well, you'll be better at higher res?

Feel free to contradict me and abuse my post