I have heard of several lords who would sit on a thousand or more bushels and just let it rot because they said it wasn't worth it, regardless of price so your not completely wrong.
What does it require to put up sell offers? I can understand not wanting to waste gold/hours on buy/sell offers that won't get touched, but if they feel like an extra 50 gold isn't worth a single click then they need to be bumped down to knight in a poor region where 50 gold means something.
