While I agree there is inconsistency of "enforcement" of the use of lavatories on AA domestic flights the major breaches occur when FAs are working the plane with their carts. I fly in the front all the time (AA's very good to its ExecPlats for comp upgrades) and seldom face delays in using the washroom due to passengers from the back cabin lining up to use the one in front. More inconvenient is when the pilots use the loo and FAs block the aisle with a food service cart so nobody can enter the galley/door area. Pilots generally tend to linger and chat, keeping the loo in "lock down".

While I admit to being mildly irritated by the sight of a mere coach passenger transgressing on our hallowed loo, it's seldom a never ending flow of violations.