I would assume they placed them there because they were from the intertestimental period and belong there. Both Jerome and Luther agreed that they were edifying for the Church to read, but not for forming doctrine. It is not the placement that is at issue, it is whether or not they are inspired. The Jews never believed so and did not include them in their canon. Jerome did not believe so.
The practice of the Church up to the time of the Reformation was to follow the judgment of Jerome who rejected the Old Testament apocrypha on the grounds that these books were never part of the Jewish canon. These were permissible to be read in the churches for the purposes of edification but were never considered authoritative for establishing doctrine. The Protestants did nothing new when they rejected the apocrypha as authoritative Scripture. It was the Roman church that rejected this tradition and ‘canonized’ the ecclesiastical books.
The King James translators never considered the Apocrypha the word of God. As books of some historical value, the Apocrypha was sandwiched between the Old and New Testaments as an appendix of reference material. This followed the format that Luther had used. Luther prefaced the Apocrypha with a statement:
"Apocrypha--that is, books which are not regarded as equal to the holy Scriputres, and yet are profitable and good to read."