Even Lubavitchers would join litvaks in denouncing the crazy cults of Messianic Jews, Lev Tahor, Eliezer Berland, or Reform Judaism. That’s not hate- it’s pointing out he truth and loving all Jews, and hoping we can save them. We don’t hate the innocent brainwashed Jews of extreme meshichist chabad any more than we hate the brainwashed youth of Lev Tahor. It’s not their fault. “Hater” is the Lubavitch hijacking of the liberal “racist”, designed to change the subject into an ad hominem and deflect from the issues.
It was kind of understood that everything the rebbe shlita (as per signs in 770, he’s the Rebbe Shlita, feel free to stop and and see for yourself- pok chazi) said about his father in law “nosi hador” was meant for himself. Later he bacame more explicit and said things like “Moshiach’s name is Menachem” “moshiach miyad”, (miyad being roshei teivos for dov ber, yosef yitzchk, menachem mendel) and moshiach mamash (mamash being roshei teivos for menachem mendel schneerson). And as per daily rebbe vido #244, you can watch him waving along with the yechi adoneinu song. In basi legani he also said that Hashem loves 7, and just as Moshe is the 7th shepherd and redeemed the jews so too moshiach will be the 7th shepherd (the last Rebbe was the 7th Lubavitcher rebbe.)
Not hatred. He made the claim.
As for who said it’s wrong, Adoniyahu claimed to be king as is viewed as a rasha for doing so.
Nasi hador is a ridiculous title for a guy who had 1 tenth of the followers at his funeral than Rav Shach zt”l had. Yet he called himself that.
(Once we’re on the topic of Rav Shach zt”l, Rav Shach zt”l was rather clear in his denunciation of Lubavitch and called it avoda zara. In return for his kind-hearted efforts to save a large portion of klal yisroel from eveira, he was called “Shach” and “mibnei banav shel Haman limdu torah bebnei brak”. He was not denouncing Lubavitchers, which is a big difference. )
Rav Aharon Kotler zt”l, the gadol who rebuilt Litvish America, also warned about Chabad.
That was when the Rebbe was alive and “yechi adoneinu” was sung to a living person who could at least have been moshiach based on the fact that he was alive, though the odds were greatly against.
Now that the Rebbe has passed on , yechi adoneniu has become quite problematic. Rav Chai mKohn of the KAJ used to check the shochtim at Rubashkin to make sure they believed that the Rebbe was dead instead of alive, even if they believed he was moshiach. Rav Aharon Feldman shlit”a, who is on the moetzes, has the same view. So according to both of them, the ubiquitious “yechi” yarmulkes around Crown Heights are apikorsus. Lubavitchers say in return that they are just “snags” (“Snags” being the perjorative term used by American Lubavitchers to describe litvaks, short for misnagdim) who don’t understand chassidus. In other words, yes those gedolim hold “yechi” Lubavitch is apikorsus , but it’s only because they are litvish. Of course Rav Menashe Klein zt”l , who was a chassidish posek, said the same thing.
Feel free to look at chabad news websites and see how the “yechi” yarmulkes are everywhere to understand that yes, it’s malei apikorsus according to many gedolim. Lubavitchers have teirutzim for everything, but why not kaleich eitzel yafos and avoid the problematic apikorsus and avoda zara?