Wading in.
I am a dog owner. A responsible dog owner. My dog is not allowed anywhere near any small children. Even familiar children (ie my own nephew).
I pick up my dog's shit. I do not allow him to jump on anyone. I have done my best to train him, but I do not let him off the lead anywhere near other people, unless it's at a dog park. I am always vigilant around other people.
I think this is the minimum that any dog owner should do.
For those who have children who are terrified of dogs - you are doing your children absolutely no favours by allowing them to be scared in this way. There are dogs out there in the world. Teach your children to cope with them. Not to throw a strop and get upset, because this will potentially attract a dog's attention and/or upset the bloody dog, causing potentially further fear on both sides. Teach your children how to behave around animals, rather than reinforcing their fear.
I am appalled whenever a parent allows their child to rush up towards my dog. I also had to intervene as a father stood talking to his mates at a bbq, completely oblivious to his child going over to my tied up dog and trying to remove the bone that my dog was chewing on. Seriously?! Thankfully my boy just moved his bone out of her reach, but he was annoyed. After that incident I became a hell of lot more proactive in directing other peoples' kids.
It's simply irrational to be scared of all dogs because one bit you/someone you know. I myself was bitten twice as a child. Once taught me not to annoy sleeping, highly-strung terriers and the other occasion taught me that cute puppies can be nippy without being vicious.
I think I shall conclude my essay here. I understand that there are terrible dog owners out there and I have seen (like everyone else) horrible maulings by dogs that are subsequently put down. These are rare and truly awful. But, the overwhelming majority of domestic dogs are not going to rip your or your child's face off when they bound up to you at the beach.