For me it comes down to: where you would rather the FAs are: waiting in line or at the gate, potentially already on the plane.

Of course there is no be to be rude. That cannot be excused.

Where there are no dedicated security lines then signs should be erected.

And, if a FAs says, "Excuse me, as a crew, I go first", I should be able to say "I think I am going to miss my flight, can I go first?".