Bacause at the moment, the "Shipyard" option is only there when required. ie: If you can't buy (or sell) a ship, then you can't store a ship. Why offer an option you can't do anything in?
If you can now (in 2.2) get another ship to a station, then you can use the ship storage aspect of the Shipyard![]()
You keep saying this word "shipyard" but I don't think you quite understand what it means in relation to the game and the gameplay mechanic in question.