That's kind of a red herring. Nobody ever made them marry, is making them marry, or will make them marry. I don't know of anybody who has ever advocated 'making' people marry. What I alluded to in my response, was a well-known cultural cluster of marriage, religion, education, personal responsibility and motivation.
"Is there some other way to “fix” them ?"
Restoration of that cultural cluster: not "just" marriage. but all the components wherever one can have an impact.
BTW, this is something I just ran across today: an article about the Talitha Kuom Institute (Link), which seems to be one of those components: a church-sponsored therapeutic-nursery project for kids in Waco, TX who are in 4th and 5th generation poverty ("poverty" doesn't begin to describe it: it's 4th and 5th generation family and personal disintegration) where the volunteers are trying to literally rescue their brain development by giving them what used to be called ..."mothering".
That's one way. One in the cluster. In my opinion, our choices are
There are many attempts and more speculation along these lines. None seem to be based on a good scientific basis, seeing that our understanding is so limited.
The usual subtext in sociology research is to come up with some public (government) policy. This is a problem with the whole field I think, it tends to corrupt research. I don’t know if this particular set of problems can be positively affected by public policy at all.
Some proposals regarding marriage specifically include encouraging marriage by tying it to some government benefits; this sort of policy is what this study seems to be intended to evaluate.
Absolutely. Restoring the natural family and personal responsibility, based on a cultural standard of morality, is the only answer, and is not a quick fix. There is no quick fix.