Many years ago I was having lunch with a customer and some colleagues in a central Birmingham Chinese restaurant of some note (perhaps not Super-Swanky, but at the time probably one of the best in the country). At one adjacent table was a family with a lovely, lovely toddler. At the time few of us had children, but we all came over broody at this kid gurgling away, enthusing about the bits of food he was eating and generally being enchanting.
At another adjacent table was another work group. They complained about the child, making the "we don't come here to have children making a noise, etc, etc".
The manager came, and without any further ado threw them out. The group that complained, that is. Jokes about Chinese restaurants being in league with the triads aren't funny, but the waiters were the sort of guys you don't argue with. They came over to us afterwards and said that children are their future customers, and sorry for the fuss.
Pre-children, we'd already long decided to stop eating anywhere that said "no children", on the grounds that it was a handy shorthand for the sort of places we didn't like. As impecunious students in the early 1980s we had lunch in Marco Pierre White's original place in Wandsworth (by God, it was a good meal) and that was stuffed with local children.
Since then, I've chosen my restaurants. I took my children from when they were babes in arms to appropriate places, always at lunchtime, always to the sort of places where there's always something to pick at and you can order an assortment --- tapas, Chinese, etc. It gives them the idea of what a restaurant is, and allows you to step up the game. It gives them the idea that a restaurant is a place they can feel comfortable in, and will get good food even if they don't know what it is.
Which means that over the years (they're now 12 and 14) we've eaten in a Venetian place where the main attraction is multiple courses of whatever fish they have cooked however they want to cook it (younger had been itching for one traditional dish all week, so did manage to negotiate their cooking it for her even though it wasn't on the menu, for which I noticed they didn't charge). We've eaten in dockside Sushi places in Tokyo, where the sight of a blonde gaijin child asking for fatty tuna caused something of a stir. And more importantly, we can dive into literally anywhere when away from home confident that they'll eat well and enjoy themselves --- being able to walk down a street and just say "that looks nice" without having to negotiate if they'll eat it, or if they'll be able to wait, is a real boon. It also means a big treat is eating in Balti Triangle curry houses for a tenner each, which makes for an excellent evening out en famille and costs little more than fish and chips.
They've never kicked up a fuss, although once at 18 months in a hotel restaurant in Cherbourg younger got close to it, and we've only once had a meal where the kids didn't really like any of the food. If I thought I were upsetting adjacent adults I'd be mortified, but the only way you can be sure your children won't be fussy, impatient teens (just as likely to piss off the grown-ups) it to acclimatise them from an early age.