If the marriage act were to be changed to accept ssm it doesn't mean that it will be trashed . It will still be about the commitment of two people .
Marriage has changed over the centuries . The version that we have today is not exactly the same as the the version they had 500 years ago . It has evolved as times have changed . Just as churches have softened their views on things such as contraception and sex before marriage as an example .
When are people going to get their head around the fact that there are same sex couples who form long term relationships just as hetero people do ? They even raise children these days .
Who knows ? They might respect the institution more than people do now .