There should be a limit, maybe 3.
After three failed marriages, it's you!!! Doesn't mean someone is a bad person, has cooties, etc... just that they're stupid and keep making the same mistakes over and over again. In theory, marriage is supposed to be a legitimate contract between a man, woman and God (or any variation on that if you're Mormon or gay) not some game you keep getting do-overs until it gets perfect.