I kind of covered that already, but to put it more clearly: (a) by blaming the decision to include them on earthy powers who stopped following God, and (b) identify/double-check the latter looking for self-contradictions and discarding text that has them. According to my rusty memory, both of these arguments were used explicitly (but I freely submit that I may have confused Luther with other Protestants).

But, for example, what theological reason could have been there behind taking out the books of the Maccabees?

A further point: there is Luther's famous line about women and booze. But more serious arguments behind that were again literalist: the rejection of these as not Bible-based, based on counter-examples within the Bible.

Finally, a meta-point: something everyone emphasized in the debate is that fundamentalists aren't really orthodox, but introduce something new under the appearance of turning back to orthodoxy. But the other side of this is that this new they bring can also develop into something progressive, as the movement grows older. I contend that that is the case with Luther's reforms - mother-language Bibles, less hierarchic church, booze and women, discussion rather than guidance ended up as the hallmarks of a much nicer form of Christianity.

_{*Lunatic*, n.
One whose delusions are out of fashion.}