The problem here is that what has been nothing more than a behavior and tendency among a marginal portion of the human population is now being foisted upon the majority and imposed as somehow an 'identity' when for ages it has always been recognized as nothing more than a sexual jumpsuit people jump in and out of. And to go even beyond calling it an 'identity' and to attach "rights" to it is even more idiotic.
Redefining marriage and the longstanding traditions which represent the collective wisdom of the ages and civilizations is like changing measure of a yardstick into centimeters and insisting on using it as a yardstick. In both cases one cannot change the definition of that thing, and still use it as a reliable source for measure.
Every society and its institutions are intolerant of some sort of behavior. Unqualified toleration is not only nonsensical it is impossible and lethal. Society can shun or frown on certain behavior or attitudes that it deems unjust or in some way inappropriate. Intolerance always occurs in terms of a society’s or its institutions’ premises. But since we are in a "democracy" where we are in an endless game of "rights", even "right and wrong" concepts become a matter of majorities and "tolerance".
I think that gay and lesbian couples purse to attach marriage definition in their relationship for number of reasons. One of them, equal rights under the Constitution, another is to benefit from tax laws and insurance policies and such. I have no problem whatsoever for them to marry and call that relationship marriage.
Throughout history, there were many injustices done to minorities whether they were protestants in England and France, Molokans in Russia, Jews in medieval Spain, or being woman in general. Each time, the society persecuted them and created deep animosities citing traditional conservative values of our predecessors