It's a rogue court in that it's not derived from the will of the people. In democracy, the people are sovereign and have a say in what their laws are. American[1] citizens don't have a say in what international laws are, they can't invalidate them, so why should they be subject to them?

This is akin to the Nuremberg trials, where Germans were tried by foreigners, without the consent of German citizens... The major difference is, the Germans lost the war so Americans got to impose their will on the vanquished. America did not lose a war to India, so why should Americans be judged by this Indian?

[1]: I'm not American, but like the US, I also wish my country was only subject to the laws of my people.