I am familiar with the terms, and even had a vague notion of their origins. I rather disagree with this statement, though: ". . . are slowly stripping them of their emotional fangs."
While I can usually manage to have no opinion (or at the very least, none I feel the need to express in public) about couples who choose to live together with getting married, that is not true when they have children. IMO, the fact that we not only have these terms in our (general) culture, but they are becoming neutral or even positive is somewhat nauseating. To me, they will ALWAYS have "emotional fangs."