I post this because I believe that that is what marriage is at the end of the day- a legal construct that two people make in front of witnesses to assert that that they wish to be considered a "unit" so that there is no confusion if one of them were to die over who was to inherit and so on.
It IS true that 99% of couples who marry are in love- why else would they wish to join themselves in such a way otherwise?- BUT this does not mean to say that long-term cohabitees are incapable of having devoted, loving relationships.
To me, marriage ITSELF is not about love- it is about making clear a person's position to another individual and this is why I believe the act of giving cohabitees similar "marital" rights is wrong- they simply have not asked to be classed as married.