The commenter noted that no small part of it may be due to the fact that the Church will not marry a couple in the botanical gardens, for example, or at a Renaissance festival. I think she may be partly right, but if she is it is only because most Catholics have not been taught the theology behind the Sacrament of Marriage. When you understand the sheer beauty of it, no botanical garden or Renaissance festival can compare.
Why the Wedding Must Be In the ChurchSo, let's explore it. The Catholic wedding must take place inside a Catholic Church. Why? Because the Church represents the new Garden of Eden, free from temptation or stain of sin. It is in this new Garden that we find the new Adam, the groom, waiting to receive the suitable partner which God has promised him, the bride.
Why the Bride's Father Gives the Bride AwayAs the ceremony begins, this Bride, the promised partner who is the new Eve, enters the scene and is escorted lovingly by her Heavenly Father, represented by her earthly father. She is veiled, and Adam's anticipation builds as she comes closer. Finally, God entrusts his new creation, this new Eve to Adam as he gives Adam her hand and Adam at last sees the face of his new partner.
The Vows, The Priest, and The EucharistThe two exchange promises to be obedient to God and to one another, to love one another faithfully and exclusively all the days of their lives, and to always remain open to the gift of life. Through the hands of the priest, Christ not only witnesses and blesses these vows but then serves the couple their first meal together from the tree of life in the form of the Holy Eucharist. Through the Eucharist, Christ literally enters into the couple and confers upon them special gifts of the Holy Spirit which give them the graces needed to fulfill their vocation as spouse and parent.
The Witness of the Community
These things are done in front of the Community of Believers for good reason. The community who show up are not merely present to witness to the vows between the couple. Their presence is their promise to support them on their journey to serve Christ through their service as partners for life and parents of the next generation.