I also have changed my share of poopy diapers having three kids and two grandkids. I would never think of changing their diapers poopy or not while right next to someone. That is just gross and rude.
Wow no sympathy for the parents of young ones here I must say. as for the changing the child at MGM during the little mermaid show what is the big deal really like the kid cares where it gets changed.
As a parent who has raised young kids I can say with confidence that it isn't a matter of whether the kid cares or not. It's whether a number of other people crowded together in the seats of a theatre should have to see and smell feces during a show. The answer is No. The parent who did this was inconsiderate and selfish, refusing to miss a minute of the show and not caring how many other people's experience was ruined.