What should the parents do? Never leave the house with the child, because its crying could annoy an adult?
Depends on where you’re going. The park? Feel free to bring the baby. A movie theater? Doing that makes you an asshole since you can hire a sitter for an evening. Going on vacation to an area close enough to drive? Go ahead and bring the baby. Going on a plane for a weeklong vacation in Hawaii? You’re being an asshole to the others on the plane.