"Just paperwork"? No. Hugely important paperwork that changes your rights and duties? Yes.
I am getting married sometime in February. We will go down to the courthouse and sign papers. We are doing this because it will make our lives easier in several ways and because it will grant us some protections. To us, it doesn't have a lot of emotional meaning. Our commitment was made long before we decided to sign the papers and, yes, we see it as paperwork (considering all the bureaucracy involved, it is hard not to!).
However, we don't impose our views on anyone else. If a couple decides that those papers are emotionally important and want to celebrate, great! If a different couple feels the religious side is more important, I will happily sit through a service and toast them. To other couples, the paperwork represents a struggle for equality and I will happily cheer them on. If it was necessary to go through the paperwork because of military, health, financial or whatever reason, I will celebrate when the couple tells me it is the right time for them.
I only get peeved when a couple wants me to celebrate every single little thing as though it was a milestone. Sorry, if you are celebrating "the day we file our paperwork", then you are celebrating inch marks, not milestone, and that becomes all about you, not about an important event.