Yes, I do think people ascribe a moral judgment. "Good" has become synonymous with "healthiness", as it comes to food. And, frankly, good is a word absolutely loaded with moral implications. The attributes you mentioned, willpower and wisdom, are moral qualities.

See, you are seen as weak-willed if you 'give in' to the desire to eat something not deemed healthy by society. Gluttonous. Unable to control yourself. A danger, therefore, to yourself and others.

And that, right there, is moral judgment.