Just as other sacraments, like Baptism. It is part of the Community of the church. It is the Church’s sacrament. The marriage is a witness to the church and the world. Within the context of the community’s worship is the ideal place for it. This is a standard. I’m surprised that you didn’t know this.
The fact that its become a circus show in the secular world has made it become more of a private affair, and its leaked into the folks in the church, because all the brides want their big day. Also, with the amount of family and friends invited that are outside of the particular parish, it is a practical concern of fitting everyone in the building.
However, there are some very good reasons for not having these liturgies take place during the Anticipated Sunday Mass. Unfortunately, as I am sure you have seen since you have played at weddings (and I have helped with the coordination of same), these events take on a life of their own. Often, the couple will bring their own readers and these do not, most of the time, know how to proclaim the Word, let alone anything else associated with the liturgy. I witnessed this last Saturday when a Quince Anos liturgy took over the Cathedral’s anticipated Sunday Mass. The readers were horrible and they proclaimed the readings from pieces of paper (a big no-no). My parochial vicar (who had served as the Cathedral’s first rector) was the celebrant and he was none too happy. He left guidelines behind for his successors, but, they seemed to have been ditched.
Then, the paparazzi show up, again, as in the case of the Quine Anos. They are most distracting, taking pictures of the readers, the couple (in this case the young lady) and everyone and everything, even those receiving Holy Communion. My PV also left strict guidelines, but, they got tossed aside. He was none too pleased.
Granted, not all of these take on strange manifestations, but, the couple (and the family of the young ladies celebrating the Quince Anos) need to take into account that this is, first and foremost, the parish’s anticipated Sunday Mass. Especially since we are in the Lenten Season, the decor and decorum of the Church need to be respected. This brings me to another issue. The wedding parties (and the Quince Anos, for that matter) tend to be loud and proud, thus removing any sense of respect for the fact that they are in the House of God and not in a recption hall. Any bantering and talking (and cell phone use) needs to be done outside, not while people are trying to pray. There is also the issue of punctuality. There have been times when both the bride and the Quince Anos party have been late. This is the parish’s Mass; they need to start on time.
As far as convalidations are concerned, Fr. David makes some excellent points. Having assisted with the coordination of these as well, the simpler the better. While nearly all of the ones that the first rector did were in the context of the Holy Sacrifice of the Mass (including the baptism of the groom prior to the nuptial Mass), these have always turned out well. The couple still goes through the required meetings with the priest, they take their FOCCUS tests and go through NFP and have a sponsor couple. I actually enjoyed coordinating the convalidations more than the weddings because the couple in the convalidation was just happy to have their marriage blessed. These, in fact, were some of the nicest because there was little to no pretention. That is not to say that the majority of our brides were behaving as such for their weddings, but, these were a lot calmer and no one was trying to do a runway style show.
Something else to consider, as Fr. David pointed out, is the fact that if the wedding is held within the confines of the parish’s Anticipated Sunday Mass, then the readings for that Sunday must be used, as well as the propers, especially if we are in the seasons of Advent, Christmas, Lent and Easter. Even if the wedding takes place outside of the Anticipated Sunday Mass, the liturgical rules for the seasons also need to be followed (no Alleluia, etc). The fact that the Roman Missal has prayers, propers and readings associated with the Nuptial Mass means that the Church considers these liturgies seperate entities that do not necessarily have to be joined to the Anticipated Sunday Mass.