Every little opportunity to murder someone that isn't patrolled by armed guards isn't a "vulnerability", for most sane people this is not something that would cross their minds. The solution for the few outliers isn't to live in underground concrete bunkers.

Although few of the changes made to airport security since 9/11 would have hindered those terrorists. Theoretically the box cutters should have already been stopped by the X-Ray and that hasn't significantly changed. The only substantial difference is that now we lock the door to the cockpit, something we should have been doing since the 80s when airline hijackings were common.