I am pretty sure a terrorist would (a) practice smashing bottles until he can reliably create a weapon and (b) smash the bottle before boarding the plane, in an empty bathroom (I have been to international airports where no flights depart from an entire section during the night, yet passengers are free to wander around or sit in those sections), and just carry it on board because there are no security checks before boarding the plane.
"And the knives rely on serration to cut through steak so are very dull."
So you think a somewhat dull serrated edge could not be used as a weapon? Prisoners manage to use far less effective weapons to kill each other; why couldn't terrorists do it?
"given that every country in the world has a TSA"
What is your point? Everyone has a public display of their airport security? Do you think that it is impossible that everyone just wants their citizens to feel safe and that the point of a public security check is to do just that?
And the knives rely on serration to cut through steak so are very dull.
And given that every country in the world has a TSA and abides by almost identical rules I would guess that there is a lot of people thinking about ways to make us safer. Why isn't the status quo the safest yet reasonable measures we have ?