Why is it that Protestants and Jews do not believe in Tobit, Judith, Maccabees 1 &2, Baruch, Wisdom, and Sirach? I am with the understanding that they do not believe as Catholics do that the books were inspired by God.
Most Protestant churches do not recognize the inspiration or authority of these books. However, they are still used in many churches today (such as Episcopal churches).
The authority and authenticity of the seven books you mention has been disputed through the centuries (along with some additional chapters in Esther and Daniel, and the rest of the books Protestants refer to as "apocryphal"). Even the Roman Catholic Church did not officially recognize the authority of these books until 1546 at the Council of Trent. The Roman Catholic Church still calls these books "deuterocanonical" (meaning that they were on a "second" list of books beyond those initially recognized as canonical).
The Reformation began to take place prior to Trent, and the Protestant Bible contains only the books that the church had officially recognized recognized prior to Trent. Before Trent, the canon had stood fixed since the earliest centuries after Christ's first advent, and the Old Testament had been canonized even longer.
The Protestant argument against including these seven books in the Canon has several elements, including but not limited to the following:
Dr. Joseph R. Nally, Jr., D.D., M.Div. is the Theological Editor at Third Millennium Ministries (Thirdmill).