Other reasons why MH is not the “language of the Jew” are:
(a) Its origin is actually anti-Jewish. The creators of MH did so because “it is not possible to be a nation without a national language” (see Eisentein’s encyclopedia, ‘Ivrit’). This of course is Apikorsus, because Jews are a nation not like other nations – whereas other nations need a common spoken language, we only need the Torah to make us a “nation”. We are no more or less an “am” if we have or do not have a common language, common food, or common geographic boundaries. The idea was that MH will make us into a “nation like all nations”, in the same way that some fool may say that all Jews should eat bagels and lox because without doing so, we will be less of an “am”. And even though those who speka MH in Bnei Brak today do not subscirbe to this heresy, we do not consider this language the “Jewish language” because it was created to actually change the definition of what “Jewish” means. In The golyon Maharsha, quoted by Rav Reuven Grozovsky in “Bayos HaZeman”, there is brought a responsa of Rav Yaakov Sasportes, a great combatant in the fight against the Shabse Tzvi y”s. He says that Shabse Tzvi actually intorduced some positive, even obligatory practices into Judaism. Performing Birkas Kohanim daily, even in Chutz La’aretz, was foremost among them. But, says the Ohel Yaakov, even though this is a good and positive practice, and perhaps even obligatory according to Halachha, since its origins came through Shabse Tzvi, we should not do it. The same applies, all the more to making MH our “national language.”
(b) The changes in Loshon HaKodesh that were made, both in accent and content, are unacceptable. The changing of accents from Ashkenaz to Sefard for Ashkenaz Jews is wrong. Rabbeinu Bachye writes that if you change even a komatz to a Pasach in the language, it will lead to heresy. Also, certain words in Hebrew are definitely against the spirit of the Torah. (Ben Yehuda once said that he designed the language specifically to “shtoch” the religious). Example: “Chashmal”, which means electricity in MH, comes from the Loshon HaKodesh word found at the beginning of Yechizkel which is the name of the Angel of Fire. The idea of taking the name of the Malach of AIsh and using it to mean “electricity” was the implication that whereas in the olden days we believed in angels as explanations for things, today we believe in technology. It would be the same as calling penicillin, for instance, “Rephoel.” The Debreciner Rav ZT’L actually discusses if it is permitted to use this word.