Probably wise, considering (at least) one of the 9/11 planes was brought down by hijackers with box cutters.
That said, all of TSA's regulations have been REACTIVE, not PROACTIVE. There are no documented instances of would-be hijackers being stopped by the regulations (lots of people have stupidly tried to ignore the rules and gotten caught at it, though).
I don't profess to know the magic formula to preventing hijackings, though.