@futurebird it's still a very persistent idea nowadays (he said, having only anecdotal evidence).
It seems to me it's a lingering outdated fact which used to be true and used both for and against changes in our societies. Now that the numbers tell us the divorce rate is far lower (and has been for some time), there isn't the same push to publicize that fact, because it's "as it should be." (Not sure I'm being very clear, here.)