Yes they are way too quick, it is very annoying. And if you notice, they are using it in conjunction with the beverage trolley cart in an effort to discourage coach passengers from using the forward lavatory (note "forward" not "FC" lav). I was once on an AS flight that when the seat belt sign went on the FA's ran around locking the lavatories, this went on/off for hours. Another flight sitting at SEA waiting for a gate, FA on the PA admonishing a FC passenger for unbuckling seat belt. compare to AA waiting for gate at DFW and people are going to the lavatories and no one says a word, much more reasonable I think. My thought is that it might be a PR attempt to create the image of a safety conscious airline, counter-act the negative PR resulting from government investigations of their faulty safety record.