It matters because the snub shows a lack of respect for Israel as an ally. It matters, as well, because it sends a message to enemies ov Israel that there will be little pushback from the United States if Israel is attacked. This message is not lost on Iran, Syria, Hamas and Hezbollah. War is coming soon to the Middle East and it will be bloody. Israel will do what it must to survive and the United States will know only afterwards. Other US allies will take note and react accordingly.
And some demented mis-elected old man making a phone call will make a difference in all that?