TSA Agent's View On Knives On Airplanes

I spoke to a homeland security agent the other day and this is the reasoning behind the TSA and the Obama administration allowing small knives on planes:
The TSA's job is to protect the airliner/air plane, not the passengers on board the airplane.  f a person uses a knife to harm someone, they are hurt or kill someone, but they are not going to bring down the airplane.
And the reason why the TAS won't allow you to bring large amount of liquids on board?:  A few years ago, some terrorists tried to use a large bottle of Gatorade to bring down the plane with liquid explosives.  They drilled the bottom of the bottle out, poured out the liquid and replaced the Gatorade with the liquid explosives and Tang.  Since they drilled the small hole in the bottom, the seal was still intact.  So, they had to come up an amount that was safe and that was  3 1/2 ounces.
So, basically, the TSA is out to protect the airplane and not so much the people on board.
So, you can watch the TSA at work here: