I think the US justifies it by reasoning that people here who are in poverty still have a higher standard of living.

But it's a secondhand standard. Nothing wrong with that, just that if people didn't throw so much perfectly working stuff out then the poor here wouldn't have all those things. True poverty is a lack of health, a lack of food, and a lack of housing... we have all those here.

And, you can't sell secondhand stuff for food either, because it's crappy and nobody will buy it. So you end up drowning in stuff that other people didn't want and you STILL can't eat. I doubt there are many people who realize that.

And as for housing... we have higher standards of housing. That means that people can't build a simple shelter without paying for permits and inspections and making sure it's up to code. A risk of fire is not quite as important as a definite death from cold!