Perhaps
perhaps they looked at their list of every customers iTunes library of legally purchased music and found zero people had paid for more than about 30GB of music. I'm sure by now they are able to extrapolate what a heavy user will require based on spending habits of their top customers. Given the classic doesn't really do video there can't be many who even filled one with music let alone legally.
Obviously there will be some nerd along to explain how much better lossless MP3s sound through their iPod headphones, and that they only get 37 tracks on their iPod before it's full...