With the Helios accident we have one example how restricted access can result in a preventable desaster. On normal flights you have sometimes deadheading crews which can be of great help in difficult situations. Wonder why the FAA thinks now, that the danger from the passengers are that much greater now.
I think to the contrary, that today nobody with a boxcutter will make it through the aisle, because passengers will intervene.
So what rationale is behind those changed regulations?
Solving a non existent problem by creating several new ones?