Quick background about the Canons of Scripture:
The Jews put together the original collection of books, equivalent to our Old Testaments. It came in three parts, which are, in descending order of authoritativeness for them:
1. The Law, the Five Books of Moses: Genesis, Exodus, Leviticus, Numbers, and Deuteronomy.
2. The Prophets, which include books collecting the prophecies of prophets and historical books in which God's will was prophesied: Joshua, Judges, I and II Samuel, I and II Kings, Isaiah, Jeremiah, Ezekiel, and the Book of the Twelve, broken out into the twelve minor prophets whose books close out our present Old Testament. (Note that I and II Chronicles and Daniel are not in this list.)
3. The Writings, including the other books of our Old Testament.
The canon of the Writings was never carefully defined until nearly the time of Christ.
The Jews of the Diaspora principally spoke Greek and were often not expert enough in the Hebrew language to understand the books as they had originally been written, in Hebrew. Therefore Ptolemy II Philadelphus, King of Egypt, ordered a translation of the Jewish Scriptures to be done into Greek for the benefit of his Jewish subjects. This is the Septuagint. Other books were around then but not considered Scripture, and still other books were written later, and they never made it into the Septuagint. Enoch, Jubilees, III and IV Maccabees were examples of the extracanonical books that weren't included.
Later the Jews of the Holy Land questioned books written after the time of Ezra or which were not extant in Hebrew, and shrunk their canon to only books that were not questioned by those criteria.
The Christian Church, mostly Greek-speaking at first, used the Septuagint, adding to it the Gospels, the Epistles, Acts, and Revelation. A few other books were considered but ultimately rejected as part of the N.T.
Jerome, the great scholar of Scripture in the Fifth Century, questioned the books in the Septuagint which the Jews had rejected, but ultimately translated the Scriptures according to the full canon.
The Eastern Orthodox regard the Septuagint as Scripture. The Catholic Church regards all but three books of it as Scripture: I Esdras, which duplicates Ezra; II Esdras, an apocalyptic collection of prophecies attributed to Ezra; and the Prayer of Manasses. (But the latter is used as the canticle Kyrie Pantocrator.) Most of the Protestants, following the Jews of the Holy Land and Jerome's scruples, rejected the Septuagint books that weren't included in the "Palestinian Canon." And the Anglicans and Methodists, again following Jerome, regard the second set of books as a sort of "second class Scripture" to be included in Bibles and read but not used as the basis of doctrinal teaching. Most modern Lutherans follow this same view. And the Council of Trent reacted against the Protestant rejection of the deuterocanonical books by formally decreeing them as Scripture.
So, at rock bottom, the answer is that nobody ever counted III and IV Maccabees as Scripture, with the exception of the Oriental Orthodox (Coptic) Church of Ethiopia, which has an amazingly broad canon, including them, Enoch, Jubilees, the Didache, and several other books of questionable origin. (The other Copts and Oriental Orthodox do not agree with them on this.) But with the exception of post-Jewish War Judaism and part of Protestantism, everyone has regarded I and II Maccabees as Scripture down through the centuries.