While homosexuality has long been argued to be the destroyer of marriage sanctity, divorce and adultery is more detrimental to the essence of a wedding. Wedding vows outline the inherent meaning of nuptials; to stand by your partner until death, giving neverending support and love. Where does this agreement cease? Death! Therefore, the day divorce was legalized was the day they allowed the destruction of marriage.
It isn't divorce itself which could undermine wedding vows, but the ease of divorce, and the lack of commitment on the part of individuals. This has become a throwaway society and marriages are entered into more lightly than in the past, with the idea that if this marriage doesn't work, perhaps the next one will. If it was more difficult to divorce, then people would look harder at the marriage before entering into it.