The problem is telling people it's a container is "over describing" it. We don't need to hypothesize about that. We have the space suits and burritos to prove it is not a good didactic approach. It is not removing from the definition to simplify, it is adding to the definition, exactly as I carefully showed in my description of "Iterator". An Iterator is "a thing that presents a series of items". It does not simplify the discussion of Iterator to say "It's a thing that presents a series of items out of a container, but also, it doesn't have to be a container". It's not the first definition that's "overdescribing", it's the second.