[saiya-jin]

Same logic could be applied to some 3000 persons that died on 9/11, reaction to it considering relatively small amount of people was/is extremely disproportionate. People are dying daily in more or less horrible way, left and right, and general population is caring less and less.

But we humans are emotional and irrational all the time, and harm to somebody in any way "closer" to us is felt much stronger compared to unnamed faceless victims just somewhere out there. So all is usual, as per our human standards...

[Brendinooo]

When I studied abroad in Australia I lived in a house that included two Sri Lankans. When the other American in the house and I talked about how much 9/11 affected us, they brushed it off. Sure, they'd heard about it, but they said their reaction was more like, "Welcome to the world, America." A 40-year civil war was just ending in their country (I'm probably being charitable to my countrymen to say that maybe 10% of Americans knew that; I certainly didn't), and one of them said that everyone knew someone who had been around a bombing, or had been affected by one themselves.

This is all anecdotal, but it's meant to support your point - while 9/11 was certainly one of the deadliest and probably one of the most costly (monetarily speaking) single attacks ever, it was hardly something that put us on equal footing with places like Israel and pre-2010 Sri Lanka. But it mattered to all of us a lot more because we had never seen it here, we didn't think it could happen here, we knew where NYC was, we knew those skyscrapers, etc.