I loathe children, but I hate terrible parents who refuse to discipline their child and make them act appropriately. I don't need for parents to make their kids act like mini-adults. I would just like for them to know when it's not appropriate to be loud and hyperactive. "Brat bans" are a good idea, but only if they focus on brats, e.g. disruptive children. Owners of places such as restaurants should be allowed to ask someone to quiet down a bit if they're disturbing the other customers. However, there is a problem with this. It would really suck if a couple with their kid were forced to leave a restaurant without finishing their meal because their kid wouldn't shut up. I think that, instead of being banned completely, disruptive children should be restricted to a sound-proofed separate room with the same services so that people who want to bring their kids can bring them, and people who want to go about their business can do such in peace. Obviously this wouldn't work for stores, but it's an idea.
That's my opinion on those "brat bans". To answer your question, I, personally, don't want to ever have children because I can do so many more things if I don't have one, so maybe other people think that way, as well. I'd have more money for myself, and I don't have to constantly care for anyone but myself. Having a child would restrict my freedom, which is one of the things that I value most in my life. Perhaps people have started realizing this more and more, so fewer and fewer people are having children. In addition, we have contraceptive methods, as well as abortions, available to people, so sexually active couples are far less likely to have an unwanted child.