Honestly, in my childhood opinion, it was fine, just trying out food and drinks (whether from shopping or restaurants), testing electronics and arcade games, maybe even buying some toys or going to indoor play areas.
Though the novelty of it soon worn out gradually, taking a walk and peek at around these areas for anything interesting is good once in a while, even if you're not buying anything.
Edit: on sec thoughts, should I place this in the urbanism community? And just so you know, I'm not an American, so I wouldn't know what butcherism might occur in the implementation of malls.
It's a safe place (or used to be), so you cut the kids loose to go do whatever they want for a couple of hours while you get to do what you want. Then all meet for dinner at the food court at 6pm, see a movie, and call it a night by 8:30pm.