There is a deep aversion to reading the Songs as “secular,” as if carnality — sexual and physical love is somehow not of the sacred community…
For you must not, accepting the vulgar, superficial interpretation of the words, suppose that the Canticle is an expression of carnal, sexual love.
Keel goes on to detail how both the allegorizers of Alexandria and the more literally inclined at Antioch simply refused to see in it the profane beauty of the raw passion emitting from the pages.
A later interpreter tried to have it removed from the canon. Thankfully, he was not successful… but Theodore was not the last to attempt such things:
Nevertheless, in academic circles, even the rise of humanism and the Reformation were unable to breach the solid front of typology and allegory. The humanist Sébastien Chateillon, whose intellectual honesty prohibited him from seeing anything but erotic songs in the Song, concluded therefore (like Theodore of Mopsuestia earlier) that the book did not belong in the canon. Because of this view, Calvin forced him to leave Geneva in 1545, saying, “Our chief disagreement concerns the Song of Songs. He saw it as a lascivious and obscene poem, in which Solomon describes his shameless love affairs.”