Modern churches shame Christian men for not wishing to marry single moms:
Such attitude to single moms being perfection itself is rather new. I'd like to give you an example of how the law and custom used to treat single moms somewhere about 100 years ago in my country.
First, there were no "single moms". You had widows, which were respected, divorced women and unwed mothers of
bastards illegitimate kids. Those groups were all treated differently. I'm not sure how the law treated the rights of a divorced mother before WWII. After the war, they usually got the custody but the divorce itself was considered something extremely shameful and their choice of prospective marriage partners was rather slim.
Poor widows were to be provided for by their male relatives, usually brothers. Since a woman was not considered responsible enough to raise a child on her own, the law made her brother the guardian of the child and any decision, such as education had to be approved by him. As you can understand, many men were very resentful at the idea of having to support both his own family and that of his sister. I heard stories about some relatives where the lady was left a widow with 6 or 7 children and her brother made such a deal out of it that she swore to marry the 1st man who would take her. She then married a widower with 6 kids of his own (all boys while hers were all girls).
Even though he had married her so that she could take care of his kids, he again resented very much the necessity of providing for the kids of another man and promptly kicked her daughters out of the house by the 1st opportunity so that they had to enter domestic service (there was little opportunity of other employment).
I also read that in some places widows were provided for by the community but had to take care of the orphans in return.
And what about the real "single moms", the euphemism invented for the one reason only, to take away the stigma?
A woman who produced an illegitimate kid was obviously deemed unfit to raise him herself. If the family were poor the child was taken away and placed in an orphanage. The mother then had to work, and pay out of her wages for the upkeep for her bastard. She was allowed to visit him from time to time. If she married (and yes, it did happen even back then), she had to quit her employment (married women couldn't work, of course), so it was up to her husband to pay for it. The child still stayed in an orphanage though.
Again, I heard stories of a distant relative somewhere in the 1920 or thereabout who always claimed that her pregnancy was the result of r8pe (though the man was never prosecuted) yet it didn't help her. She later married and her husband kept paying to the orphanage. Germany, btw, had similar laws about male guardians, and they were abolished only somewhere in the 1980s from what I heard.
So that was the law and tradition about single moms back then. I'm not implying we should go back to it, just providing the info:)