the lactose intolerant. people with teeth that ache with cold. people concerned about sugar/fat intake. i can think of a lot of people that underrate ice cream. it doesn't make them sane though.
As a type-2 diabetic, I pretty much avoid ice cream. Now and then my wife insists on a stop at Dairy Queen, so I do indulge in an ice cream cone the, and she will often give me a spoonful of ice cream at home (Tillamook Oregon Strawberry...yum).
Sugar-free ice creams seem to have largely disappeared in the Pacific Northwest. Dreyers or Haagen-Daaz (don't remember which) used to have one or two varieties regularly, but not anymore. Most others are in expensive pint sizes (Ben & Jerry's sized, but even more expensive).