I'm in the "not my choice but I don't think it's rude" camp. My weddings (yes, plural)
were both very kid friendly. At the first one we even had a separate kids' reception in a room off the main ballroom. The kids were welcome to come and go between the two rooms, but mostly they stayed in theirs where the caregivers, kid friendly food, arts and crafts, and magician were. They had all been sent their own invitations with instructions to bring their pjs and sleeping bags and around 10pm they all bedded down in front of a video.
My second wedding was much smaller and a completely different venue so no separate kids' reception, but we did have a special gift bag for each child that was filled with art supplies, little puzzles and games, etc. to keep them entertained during party.
Even with our kid friendly attitude, I did worry that an infant might start crying during the ceremony. I knew any Mama would immediately take the baby out to comfort and minimize the disturbance, but it still worried my "emotional bride psyche". I do think that it is up to the bride and groom to make the rules they feel comfortable with and the guests to attend or not along their own comfort lines. No hard feelings should be involved as long as everyone is up front and honest with their expectations.