Peterson reports the words used as follows...
“Adultery, promiscuity, elective abortion, and out-of-wedlock births are but some of the bitter fruits that grow out of the immorality sanctioned by the sexual revolution,” said Elder Christofferson.
https://www.patheos.com/blogs/danpeters ... ruits.html
If that is an accurate transcript of what Christofferson said then he is indeed calling the birth of a child to a single parent (or parents who have not entered into a civil ceremony to formalise their relationship) a "bitter fruit". The "fruit" of such a situation is the child, and Christofferson (likely unwittingly) has just been very derogatory to children born in those scenarios.
You will note that Christofferson uses the term "the sexual revolution" to provide his audience with an enemy. Unfortunately for him, use of that phrase shows his thinking and points of reference are seriously outdated.
The sexual revolution, also known as a time of sexual liberation, was a social movement that challenged traditional codes of behavior related to sexuality and interpersonal relationships throughout the United States and subsequently, the wider world, from the 1960s to the 1980s.
https://en.wikipedia.org/wiki/Sexual_revolution
That Apostles of the Church are 50 years behind the times should surprise nobody.