So let's all sustain for a second our disbelief and ignore all the value judgments, governments and churches involved. The crux of the issue is that the law changed to require that artificial insemination be available only to couples.
In my own country it seems adoption is also only available to couples (either legally or de facto), and it is near impossible for a father to win a custody case when divorcing.
I think the wider trend here is prioritizing some ideal of what would be the best outcome for the (future) child and most of society believing a single parent would not do as good a job as a couple, on a significant averages comparison, and that men are inferior child rears as well.
I don't know if it is true, but living in a democracy means common wisdom, anecdotes and tradition bend scientific and informed decisions.