It's the science fiction world called, "The Planet of People Who Look Before They Leap."
There are awesome marriage schools, called couples counseling, and a lot of people do just that before getting married to help expose some of the gotchas that you don't realize before getting married (lots more farts basically). Should it be "policy?" Hell no, but it would probably help new families a lot for people to do it.
what should be policy is that the educational parts of such counseling should be part of the general school curriculum. children need to learn to care for each other, to listen to each other and respect and love each other. there is a lot you can teach about friendships and relationships in school that doesn't need to be done in the intimate situation of couples counseling.
The Catholic church requires marriage school (often the priest goes over a large standardized list of questions about how the marriage will be structured to verify you've thought it all through).
From my priest friends, I've heard horror stories of couples they've managed to convince not to marry. We are talking couples who could not agree on kids, or who had major family issues or resentment, or couldn't agree on finances.
I'm not sure I agree with the parent or not, but there are a few things that I've found incredibly valuable to sustain a successful marriage long term. For example, we have the rule to never go to sleep while angry with each other. Maybe we'll be sitting in separate rooms tired and fuming at 1am, but once heads are cooled off we talk it out and then go to sleep at 2am after both are happy to share a good night kiss. I think this is huge because it prevents anger or frustration to build up and forces it to be resolved at a natural point.
Honestly what planet are you living on.