It's simple, really.
They make Bach look sexually ambiguous and through doing so, advance their anti-Western agenda.
Somehow, I guess making Bach look  "sexually ambiguous" furthers the cause of... of... I dunno, the decline of civilization, the collapse of moral values, and the end of the West.

Well, maybe not.
Mozart, Tchaikovsky and Pachelbel were all pretty good, too, so if society's mores is going to be forced into collapse through the identity slander of classical musicians, it's likely to take a while. ;-)