I dont want to labour the point as I understand that you guys are seriously pi$$ed off. But just because terrorists wear towels on their heads does not mean they are stupid.
After they have gotten airside they do not need to board an aircraft as SLF - they do not need to fly with aircraft to do damage - they just need to have access to the aircraft (wheel wells / freight holds / avionics bay etc.).
What ever you may think - crew security is as important as SLF security - I guess they just need to do it with a bit of common sense.