The Wormhole wrote:
^^That's basically the rationalization that has since been provided in the novels for why we never saw the aeroshuttle.
We never saw the Captain's Yacht on the Enterprise D either, but there's nothing to say it wasn't there.
I doubt they would have made the outline so obviously the same as a Runabout, had they known when they started they'd never need to produce it. They kept their options open.