That's the thing, innit, machtuk? Sure the human toll of 9/11 was tragic, and as a tactic it worked fairly well. It could have been better, of course, if they'd waited a few hours until the buildings were fuller. But the US loses 10x the 9/11 deaths on the road every year, and no one bats an eye, it's just 'accepted', for the convenience of having the automobile, the same as tobacco and a host of other causes of death.
The ongoing effects of 9/11 is the heartbreaking thing. Removing your shoes, tie, belt, jeans just to get to the airplane. ETD tests. Kids no longer going to the flightdeck. ASIC cards & throttle locks on a clapped out '152 at Narrabri just because it get's a Dash from Sydney every few days, HOT or NOT security awareness training, TSA groping 3 year old's because they won't stand still in the scanner, photographers being questioned or arrested because "they pose a security threat" and the multitude of other restrictions we have today all in the name of 'security'.
I would say that is a bigger win for the attackers than simply killing 3,000 people and bringing down a few buildings.