It wasn't being a grammar Nazi, it was dealing with the author's false arguments and double-standards, which are at the heart of both his own complaints, and the issues against the Israeli question. As for imperfect phrasing, it's not an off the cuff speech or Twitter post, it's supposed to be a serious policy article, where you should be thinking about what you're writing and/or reviewing it.
And this is more of that same double-standard left-wing crap. If a group not among the PC sanctified has a complaint, the relative scale of their suffering is NOT the issue, and you're crude and insensitive for bringing it up. The egregious attempts by homosexuals and feminists to compare and link their causes to that of blacks seeking civil rights are one such example. Try to point out that the ladies didn't come close to the suffering of the blacks or face nearly the legal hurdles, much less deal with slavery, and that doesn't matter, because you can't belittle someone else's feelings or sufferings, and it is the victim who defines the degree of offense and all that crap. But any time a white male points out a degree of injustice, they are scoffing and sneering about how hard it must be to be a member of a group that wasn't enslaved and includes the richest and most powerful people. Because the fact that a person of the same skin color and genital arrangement, somewhere, somehow, has wealth, power and comfort, COMPLETELY negates your own personal suffering is actually a thing.

Regarding the Christian/Jew thing, yeah. We're not comparing the War on Christmas to the Holocaust, but that was not the original comment, which was someone getting all indignant at the idea the Jews should assimilate in their own societies. The Jewish retort was supposed to be sarcastic, but the things he was indignant at what he imagined people were asking of Jews, is what they demand of Christians.

The PC crowd does not recognize a difference between private prayer, by individuals or a free association of individuals, and between forcing atheist children to pray, and they don't seem to draw a distinction between complaining about black women talking too loud and slavery, but the difference between being forced to remove a hijab and being forced to remove an American flag shirt on Cinco de Mayo is parsed with a fine tooth comb. It's okay for Christians to be told shut up and sit down, so why not Jews? The slippery slope IS a fallacy, and telling the Jews to shut up and sit down is not at all the same as putting them in gas chambers.

Actually, it's the very opposite. The point is, that while Jews all over Europe died, it was the work of a single authority. But in all-too-typical dishonesty, they will use the facts to use whatever image is most useful, such as calling the victims of the Holocaust "European Jewry" or the "Jewish Community of Europe" because that's a more useful set of victims to use in guilting France, Spain, the UK and any number of countries that did not have a policy of Jewish extermination. Europe didn't commit the Holocaust against the Jews, Germany committed the Holocaust against Europe. They murdered the citizens of Poland, Germany, Czechoslovakia, Austria, France, the Netherlands, and so on (and not just the Jewish or gay citizens, either). But not only do the Jews insist that it's entirely and only about them, but some of their advocates actually try to spread the blame to fellow victims as part of the ongoing propaganda bullshit, which includes conflating Jewish issues with Israel. The author is a frequent offender of this, conflating opposition to Israel with anti-Jewish bigotry. The latter is sometimes a motivation for the former, but there are a lot more reasons to oppose Israel or deny them something, including having a better use for your own country's tax dollars.

As a rule, few people are eager to receive someone else's castoffs. There is generally a reason why the other side didn't want them (i.e. Carter & the Marielitos), and it's not like Germany had a more egregious history of anti-Semitism than anyone else. At the time the French were persecuting Alfred Dreyfuss, Jews were doing quite well in Kaiserine Germany. The anti-Semitic stuff heard in Germany was not illegal at the time, and heard all over the world, and quite frankly, after the British propaganda reached such reprehensible depths a generation before, no one was giving rumors of German atrocities much credence.
Which is fine for them, but for people who can look it at objectively, there is no reason to indulge that belief. And in fact, given the obvious and understandable emotional issues for the survivors, maybe they should be kept out of such discussions, due to conflict of interest and lack of objectivity.