My extremely subjective take on every Pokémon and if it's cute or not. (While I do have a bachelor's degree in design, like all matters of taste, in the end "cuteness is in the eye of the beholder.") I will attempt to justify my decision based on design elements.
This Pokémon has one of the saddest Pokédex entries in the entire series. "Jumpluff travels on seasonal winds. Once its cotton spores run out, its journey ends, as does its life."
Oh, about its design whether it's cute or not?
It has all the cute elements. Round, round, round, small face, round... It shares the colors of my all time favorite, but why is it not cute? The balance of its design. While it's composed of many circles, they're places in a cross like shape. Looking at its silhouette it looks more like a model image for a chemical composition or like a nucleus with its surrounding electrons.