The bag fee thing is a red herring.

Just try taking a WN flight. It includes two bags with all tickets. Does not change the fact that people still lug steamer trunks onboard.

In the legacy context, OH space is not likely to a problem other than at the end of boarding.if the GA's monitor the size of the steamer trunks. People want to board first because they think it makes them special. They forget (or don't know) that in the good old days (if they were good), F boarded last.