If I have kids, I can’t imagine that I would bring them to a nice restaurant no matter how well-behaved they might be. But if someone else does, I’m not going to give them a hard time over it. Whatever compelled them to bring junior to the five-star trough is really none of my business. Life is too short to get your knickers in a wad over things you won’t remember 3 days later anyway.
A nice restaurant will seat the family with little ones by the door to the kitchen. If they allow disruptions to the ambiance, they will lose business.
Some of our children were fine in public, others were terrors. We never inflicted our terrors upon others. It’s common courtesy.