I don't mean to mischaracterize your post, but it sounds as though you are arguing that race has a greater influence on outcomes than whether you are raised in a single-parent home. It made me think of an article I recently read. It sights research that disagrees with your assessment.

Link: https://www.bloomberg.com/view/articles/2017-03-28/how-utah-keeps-the-american-dream-alive

It's long, but worth the read. Here is an excerpt: "By encouraging members to marry, the Mormon Church is encouraging them to reduce their own likelihood of ending up poor. But it may also be creating spillover effects even for non-Mormons, because Chetty et al didn’t just find that married parents helped their own children to rise; they also influenced the lives of the children around them.

“Parents’ marital status does not matter purely through its effects at the individual level,” they write. “Children of married parents also have higher rates of upward mobility in communities with fewer single parents. Interestingly, we find no correlation between racial shares and upward mobility once we control for the fraction of single parents in an area.”

In other words, while areas with high numbers of racial minorities did, in general, have lower levels of mobility (for whites as well as blacks), once they controlled for the family structure of the community, that effect disappeared. Marriage seems to have more of a correlation with mobility than race does. Homogeneous Utah is the real-world laboratory that bears out this theory, which in more diverse communities can be obscured by racism and racial activism."

I didn't read the OP's article, so my credibility on what caused the uncle's particular childhood is unknown to me. It seems reasonable that there are a number of variables that came into play. There are certainly people who have premarital sex who don't have kids out of wedlock, and there are certainly people who drink alcohol who don't abandon or abuse their children. Follow the correlations. Premarital sex is one of the most likely ways to create a single-parent home. The fact that "uncle" was born outside of a stable family was likely a large contributor in his case. There is also a correlation to alcoholism and child abuse: http://www.livestrong.com/article/240851-alcohol-child-abuse/ (I've heard about studies many times, this article was just the first thing I saw when I googled it). So it is likely, if the "uncle's" abusive uncle drank a lot, that the alcohol contributed to the abuse. Given that these were likely, if not definitely, contributing factors in the difficult childhood of "uncle," then it would ironic, as the OP suggests, to recount this tale and then discredit the benefits of chastity and sobriety.