I notice that whenever this topic comes up all meaningful nuance tends to be tossed out the window in favor of mere partisan bickering.
The question of the Biblical Canon and the status of the Deuterocanonical books is a highly complex one, it involves questions and conversations within Christianity that have been going on for the last two thousand years and can't be reduced to "Protestants removed them" or "Catholics added them" arguments.
Someone earlier mentioned the Jewish council at Jamnia (Javneh) in the late first century. That never happened. There's no historical record of a Jewish council held at the city of Javneh. The city of Javneh was an historically important city for Judaism in the late first century after the fall of the Jewish Temple. But there is no historical evidence of a "council" there, or that said council addressed the Jewish Scriptural Canon. In modern times there was speculation that perhaps something like this may have happened--but there's no evidence for it, there's nothing in the historical record, and nobody before the modern era mentioned it. And, indeed, the actual evidence suggests that the evolution of the Jewish Tanakh was itself an ongoing question among the post-Temple Rabbinate into the Talmudic era. Which is to say, both Jews and Christians were having their own distinct and separate conversations and debates about what their Scriptures were at the same time.
Whatever path the Jewish Rabbinate took isn't binding on the Church anymore than what path the Church took would be binding on the Jewish religion. So the question of what books belong in the Christian Bible cannot be answered by what books were ultimately accepted or rejected among rabbinical Jews in the first few centuries AD. Rabbinical authority is of no consequence in Christianity, just as Ecclesiastical authority has no meaning in Judaism. Christianity and Judaism split apart from one another, as Christians made their identity not as Jews, but as Christians--followers of Jesus as the Messiah, who embraced both Jewish and Gentile members without distinction. While Jews have their identity in their Jewishness, based on the covenant God established with them at Mt. Horeb in Sinai. Early on there isn't a firm line between Judaism and Christianity, Jewish Christians continued to attend synagogue, worship at the Temple, etc. But as time went on, as friction arose between Church and Synagogue, and finally with the destruction of the Temple Jewish religion coalesced into its own unique religious identity, one that didn't include Christians within it. And Christianity, likewise, took on its own identity apart from our Jewish neighbors and cousins. There's no finger pointing made here, it's just a matter of history. Judaism became its own thing, and Christianity became its own thing. By the end of the first century this had become rather clear; and was made more obvious in the Talmudic period for Judaism, and the Patristic period for Christianity. This isn't a bad thing, it's just a thing. So Judaism isn't Christianity, and Christianity isn't Judaism. And that's okay.
So whatever conversation we are going to have about the Deuterocanonical books should be within the context of the Church. What those outside of Christianity think about these books isn't relevant.
Now, some might think that this solves the issue: The Church said yes to these books, therefore they are in. But history isn't that simple, and the questions surrounding these books aren't answered that simply. There's no singular source that we can point to and say, "That's it, that's when it happened", as I've seen some do with the councils of Rome, Hippo, and Carthage; because we also have other councils like those at Laodicea which don't agree with the aforementioned western councils. Further, such local councils do not have the import of an ecumenical council--and no Church-wide council of the first thousand years ever addressed these questions. And any claimed Church-wide councils, such as the western "ecumenical" councils which only Rome accepts but which are not accepted by anyone else isn't going to answer this question either. Yes, the Council of Trent did affirm the canonical status of these books--and so for Roman Catholics who accept the authority of Trent the matter is settled. But those who don't accept the authority of Trent don't consider the matter settled by Trent at all.
The Eastern Churches point to the Septuagint saying that's the Christian Old Testament, plain and simple. Roman Catholics look to their own councils, and Protestants to their own confessions. But none of this actually settles the question. The question is definitively and unmistakably un-settled.
So here's, what I think, is one of the most important questions to be asked in the middle of all this: Can Christians have disagreements over the Biblical Canon and still be Christians together? Can we have these disagreements and still be biblically oriented and biblically faithful? Or is this question itself sufficient to create such division that one side can claim the other is fundamentally unfaithful to Jesus because of this? Is this a matter where disagreement is acceptable, or where disagreement cannot be acceptable? Do we need to, all of us, have the exact same Biblical Canon? Now, I'm not answering this question here, I'm simply asking the question in the hope that this can provide a more meaningful discourse for us to be having. Or, perhaps, my question is already answered in this thread: All sides saying, we cannot have disagreement, and either Catholics wrongly added books, and Protestants wrongly removed books, and the Orthodox are looking at the West being weird again.
-CryptoLutheran