voice over clearly said tht if a bal-vivah breaks it is the society's fault, but I do not think so! also statistically speaking not many bal-vivah's end!what the voice over said was that those marriages which are conducted when they are children, their likes and dislikes change when they are older and relations break. This is not their fault but the fault of the people who conducted the bal vivah, their parents.
Now usaully when a moral statement is given in BV they are not referring to the serial they refer to society. In the statement there was no mention of the infelidity, but that likes and dislikes, change in feelings which then make the relations break, which is true.
I guess its up to interpretation, that is how i interpreted it