I don't necessarily agree in all cases. Couples who fight 'rationally' may well be rational enough to see that they're not the right match, and that they should both keep looking. That's certainly been the case with me.

People who are staying together despite hating each others' guts may be doing it for reasons that will, paradoxically, keep them together for the long run, to their detriment. Sometimes the right answer is to split up.