Not sure "a major chunk of the world population" is a good way of looking at this.

Anything China does is "a major chunk of the world population". Same with India.

Which is all fine and good until you go committing war crimes on foreign soil in regions that may not have proper legal frameworks. Committing war crimes in Iraq for instance. Which is kind of where the whole ICC thing comes into play - it's not really for like, speeding tickets. The US had the opportunity during development of the framework to engage and ensure all the other terms could be fairly met. Note that the text you quoted was also an amendment to what was meant to be a living document, albeit long since ossified.