The title of this Page is phrased as a question (though without the punctuation), so I’ll give the answers:

1) Presidents don’t like Congress meddling in foreign affairs, as it’s considered a power grab;
2) It’s too difficult;
3) The US has attempted to portray itself as a neutral actor wrt Jerusalem.

And no, I don’t support the petition offered. And, those bills stuck in committees ought to sink in those committees.