Because Krauthammer's column rather makes me suspect that he belongs to that horrid category of Americans who, be it for religious reasons or for ideological ones, show a blind and fanatical devotion to the idea of Israel while not giving a damn about the real long-time interests of the state of Israel or its citizens. Which is not a unique phenomenon, there have been other conflicts in which something similar happened, notably in the case of Ireland where some Irish-American Catholics were very happy to show the IRA unwavering support, moral or financial - after all, they didn't run any risks, they weren't the ones who needed to find a way to go on living with one's neighbours even if they happen to be Protestant. But at least they were of Irish origin; in the case of Israel, it almost seems like the most fanatical and the blindest "supporters" of Israel are the Americans who aren't Jewish.
Who would you say is the better friend, someone who plays the cheerleader for every action you ever take without the slightest regard as to whether it's morally right or a smart thing to do, or someone who supports you but is willing to tell it to you straight when you're making mistakes?
Of course there are many critics of Israel (European or otherwise) who do not match that last description at all, and who couldn't even claim to be a real friend to Israel - nevermind the Israelis agreeing with such a claim. But there are also those many who do, and who are real friends, striving for real peace and the protection of Israel's long-term interests; I'm proud to consider myself among that group. If you or Krauthammer ever feel like taking a more productive stance, you may want to start by listening to what the more sensible Israelis have to say for themselves. Sadly Haaretz is behind a paywall these days, but generally that should be your first stop - other Israeli newspapers might do the trick as well.
Finally, you may note that I've been talking in this whole post about Israel and Israelis, not "jews". I happen to live in a city with a very visible Jewish minority population - which is overwhelmingly Hasidic, and mostly belonging to the considerable number of Hasidic denominations who oppose emigration to Israel on religious grounds. Yes, there are some people here, primarily but not exclusively recent Muslim immigrants, who let their devotion to the Palestinian cause blind them to the difference, but from you I would expect better. Even Iran and Hamas do their best to make that distinction (though I'll admit that may be mostly out of political convenience - the Iranians quite like having Jewish members of their parliament who strongly condemn Zionism).