The first category are the ones who will someday quote all sorts of break up stuff on their walls and end up watching every heartbreak song on youtube. Why else would such "let's cry together" songs become blockbusters?
The other kind of people (who know they are not in it for a long haul) are usually looked down upon. The fact is that the first category (heartbreak champions), after they finish all the weeping, will graduate to the level of this second category guys who by-passed the trouble of going through all the torture and realization drama.
Having said that, the probability of couples ending up together does not vary much in both the kinds. At the end of the day people move on due to various reasons which may range from a new partner option to parents' don't approve to my pet doesn't seem to like you.
The real need is to have a boyfriend/girlfriend and the stated need is true love. When two people understand this fact, they can be the happiest pair even if for a short span. The break up doesn't hurt much and you can avoid all the comedy of "your smile is my oxygen".
I respect the institution of marriage and would not want to comment on that part of life. But before that one need not feel obliged to carry the burden of emotions and worries about future and the grief of break up (at least not after you had it once). Teenage to marriage is supposed to be the best part of life and it will be so if both parties in the pair are willing to accept the real need.