Previously many days did in fact go through very complicated legal proceedings to try and do this, but many places where it matters (like hospitals) don't have those contracts so its very different from just saying 'thats my husband/wife'.

I think that's the more important bit -- having society recognize the relationship as equally valid, such that all the things that normal straight married people take for granted can also be taken for granted by gays. Unless law codifies that, it's harder to do.

Civil rights has often focused on law as a kind of behavior floor and codification of rights -- society then takes many years to catch up but its a very motivating factor.