Alternatively you know....we need to at least consider the idea that arranged marriages rely on the choices of older and wiser individuals who know more about social dynamics than youngsters and ultimately are better equipped at making choices. (I doubt it, but still...)

I consider that to be pretty likely, though how much better the older folk are at spouse choice should strongly depend on how much their kid's situation resembles theirs (and their peer's); it would also depend on how well the parent knows the prospective spouses - so the advantages of arranged marriages would probably be greatest in small, rural communities.

(Another factor is probably the age of marriage; when people are expected to marry young they'll probably make worse decisions if left to themselves)