This is idiotic advice. Many people have usage patterns that don't involve music, games, locally stored movies, or anything else that requires significant storage.
Smart advice is to describe what the additional storage allows. Then people can evaluate if additional storage is something they will need.
Of the 16GB iPads issued to our employees, I have never once witnessed one filled to capacity. Our needs just don't involve local storage that comes close to filling up a 16GB iPad.