halacha theory - Why are people going back to paskining like the Rambam?

I have heard personally (and seen in chat) people (who are not Teimanim [for whom there is a tradition to rule like the Rambam]) ruling like the Rambam. I have heard that he has the authentic tradition, etc.

Why are people going back to the Rambam over, say, the Mordechai, the Tur, the Rif, R"i Megash, Tosfos, etc?

The Rif and the R"i Megash were before the Rambam and the Tosfos were contemporaries.

Moreover, the Mordechai and Tur quoted earlier poskim, some of whom lived around the same time as the Rambam. Yet, I have never heard of anyone following exclusively the Mordechai.

I have heard (DoubleAA IIRC) say that it's possible that it's because the Rambam wrote on Kol Hatorah Kula. But that doesn't seem to be a good reason. People rule like the Mishna Brura, Chayey Adam, Kitzur over, say, the Aruch Hashulchan even though the Aruch Hashulchan covers more ground.

---

Why are there people who exclusively follow the Rambam?

Answer

If you can read Hebrew, then there is an extensive explanation of "why Mishne Torah" by a group of Talmidei HaRambam associated with Ohel Moshe who rule exclusively according to MT.

A very short and incomplete summary ( from memory ) of the above:

1. It's the only complete compendium that covers all of Jewish Observance.


2. It's written with the intention of making the average Jew self sufficient in common matters of practical halacha.


3. It's not influenced by Kabbalah or extra Talmudic minhagim or rulings


4. The Beit Yosef himself said that anyone can choose to rely exclusively on the MT. ( have to look up the reference for that )



5. It makes the point of trying to identify the origins of rulings, i.e. Torah M'Sinai, Daat Moshe, Daat Yehudit, M'Divrai Sofrim, Ezra, Chumra, etc...

EDIT 11/6/2017

Multiple have requested this quote, so I found the quote on a Rambamist website, chayas.com, which is loosely associated with the Rambamist Beit Midrash Ohel Moshe in Beit Shemesh:

Rabbi Yosef Karo (author of שולחן ערוך‎): "Who is he whose heart conspires to approach forcing congregations who practice according to the RaMBáM of blessed memory, to go by any one of the early or latter-day Torah authorities?! ...

Is it not a case of a fortiori, that regarding the School of Shammai—that the halakháh does not go according to them—they [the Talmudic Sages] said ‘if [one practices] like the School of Shammai [he may do so, but] according to their leniencies and their stringencies’:

The RaMBáM, is the greatest of all the Toráh authorities, and all the communities of the Land of Israel and the Arab-controlled lands and the West [North Africa] practice according to his word, and accepted him upon themselves as their Chief Rabbi.

Whoever practices according to him [the RaMbáM] with his leniencies and his stringencies, why coerce them to budge from him? And all the more so if also their fathers and forefathers practiced accordingly: for their children are not to turn right or left from the RaMBaM of blessed memory.

And even if communities that practice according to the Rosh or other authorities like him became the majority, they cannot coerce the minority of congregations practicing according to the RaMBaM of blessed memory, to practice like they do. And there is no issue here concerning the prohibition against having two courts in the same city [‘lo tithgodedu’], since every congregation should practice according to its original custom…”

(Abqáth Rokhél, simán 32. Translation: r. M.S. Bar Ron)