The thing is - as far as I can tell - legally this doesn't really change anything. We've had civil unions for gay couples since 2004 which afforded all the same rights except adoption (you could however still adopt as an individual).
They weren't marriages though.
I don't know how NZ does it, but unless you had a national relationships register or some equiv there probably was higher evidentiary requirements in proving civil unions as well
I just don't understand why it has been such a big issue. We more or less already did this with the Civil Union Bill. I support it, but I don't understand the people on Facebook who act as though this is some civil rights watershed moment and I understand even less the likes of Protect Marriage who don't seem to realise the horse has long bolted anyway. I guess there's some validation in gay marriage being recognised by the state as opposed to just civil unions, but part of me thinks fuck the state, call it a marriage if you want anyway. As long as the legal rights are already there you're golden.
I think about it like this - some people invest a lot of meaning into the status of marriage for various reasons. Some think it casts them in the eyes of god, others say it's a public statement of a lifelong commitment, whatever. Even if a civil union had all the legal rights of a marriage, it doesn't carry alongside it that associated bundle of meanings that marriage has gained throughout various cultures over the course of centuries. So it's access to this somewhat ephemeral aspect of marriage that is the issue here, and it's why civil unions, even with all equivalent legal rights, simply aren't enough for same-sex couples.