This, and more importantly, the fact that the "family" bit that's always quoted doesn't actually use that word in Irish (it uses 'household' instead, and remember the Irish bit has legal precedence) have been argued a number of times.
It has never been tested before the SC and I'm not sure any government is willing to risk it, either. Would need an attempt to legislate and someone to appeal it, basically.
Previous cases haven't actually tested the "family" section, in Irish, which is the critical point.
Grow up. Many people think it important... more importantly it's one of societies few problems which can be solved by the stroke of a pen so of course people are sick of waiting for it.
Might not cure world hunger but it will make many people happy and cost the rest nothing so it's a no-brainer.
If you read the Dunne judgment you'll see that she acknowledges the Constitution as a living document such that the definition of marriage can change over time. In her opinion the definition of marriage simply hadn't changed enough, as of 2006.
Notably, since 2006 we have seen a bunch of jurisdictions come to recognize gay marriage - the number of people living in jurisdictions which recognize gay marriage has almost doubled since 2006 - and the research on outcomes for children raised by same sex couples has grown and bolstered the scientific consensus that gender-combination is irrelevant when it comes to raising children. Both of these issues were cited by Dunne in her judgment.
More importantly- the Dunne judgment sought to answer the question "does the Irish Constitution require that recognition be given to same-sex marriages" which is not the same as the question "does the Irish Constitution prohibit recognition of same-sex marriages?"
We only need a referendum if the Constitution prohibits same-sex marriages. Whether it does or not would be easy to test- legislate for gay marriage, let a couple get married, and test the law before the Supreme Court.