The only two reasons why Americans let this stuff happen are:
The only reason is this:
https://youtu.be/omBSEuFTYEo?t=1668The US has done the same things as this "terrorist organization". I don't think many people will observe this day. :/
They are different though.
To put simply this "shame" is not
only because of committing an atrocious act, but because of committing an atrocious act that doesn't even benefit you!
Otherwise there is nobody that doesn't know we call USA is a colony itself that is built on graves of countless innocent Americans and is guilty of genocide. But when you look at all those atrocious acts, the regime saw some benefit in them. eg. they committed genocide in America 200 years ago to establish the colony, they committed genocide 80 years ago during WW2 to establish a hegemony, they committed genocide 20 years ago in Middle East to solidify their version of unipolar world.
Regardless of the failures (like the absolute fail in the past 50 years) they did it because the regime thought they could benefit.
Supporting Israel doesn't have any benefit for US whatsoever. It just turns USA into more of a pariah state while every day hundreds of millions of dollars of taxpayers money is being wasted (~$300 mil in Gaza daily, ~$100 mil in waters depending on how heavily the US Navy is attacked that day, etc.).
Apart from money, US casualties are piling on as well!
From servicemembers they've been losing in the region and in the navy and inside Gaza (like the Delta Force unit that got wiped out the first day) to aircraft that are being shot down (like 8-10 $30 mil MQ-9's) to the warships that are being incapacitated (like USS Laboon, USS Carney, USS Eisenhower, ...).