. For the US to actually have a law that removes any aid to the rest of the world when a particular entity is recognized seems downright childish,
The UN is a voluntary association of nations, and nations make voluntary contributions to it. If they stop serving US interests, of course the US should withdraw from them and stop paying for them.
what also seems to be implied in this law is the assumption that the US has such a powerful position in these bodies that this response will affect the foreign policy of other sovereign nations in the future.
Of course it is. The US spends a lot of money both on the UN and on the US military, and Americans expect that other nations come in line with US policies and interests in return. If other nations don't like it, they can spend their own money to advance their own policies.
The only difference I see is that one for the most part attempts to follow the law (or probably more correctly make it look that way) while the other couldn't care less. I have pretty reasonable guarantees neither are looking out for my best interests (or my interests at all).
Of course, corporations are not interested in helping you; they are interested in making a profit. That is what they way they are supposed to function. And as long as they do that within the laws and boundaries we, as a society, set them, that is a good thing.
When economies are run in a way in which entities try to look out for the best interests of the people, that's called socialism or communism. It seems like a good idea and sounds good, but it just doesn't work in practice.