When did buying a movie ticket mean that everyone else in the theatre had to be as still as a statue? If you really need complete peace and quiet to watch a movie, either buy up the tickets for the whole theatre or rent it and watch it at home. Otherwise, there are going to be people at the theatres with you, and some of them will probably annoy you. Most of them paid just as much to be there as you did. Maybe the little kids got in free.
I've never taken a young child to anything not rated G, but you guys are a tough crowd to please. Some people will bring kids. Some will text. Some will talk on the phone. Someone's phone will ring five minutes after the "silence your phone" message. Some will talk the whole movie. Some will get up repeatedly. Some couples will make out. Do these things irritate/distract you because they are unexpected, or just because they are rude? If you go into any public place and expect none of those things to happen, it is your expectations that are out of whack.
I have kids and I wouldn't take them to anything not age-appropriate. But I have enough empathy for other parents to not kill them