Originally Posted by
zombietooth
Agree with you on all points. However, in this case, OP stated that there was plenty of space, seemingly removing the discretion of the FA/GA in that regard. However, since they have all of the power, we are always at their mercy. The only Ace in our hand is a willingness to miss one's flight. The complications resulting from having to find and remove a checked bag in that case can cause even the most strident GA to yield. However, I would never recommend taking any but the most conciliatory tone with them in these situations.
As this is a domestic leg, why would anyone find and remove any checked luggage if you fail to board? When one surrenders a bag to be checked to a destination in the lobby, you accept the fact that the bag will be transported to that destination. The claim check given to you in the lobby as a way to claim it at the destination printed on it kind of confirms that.