If a dog comes up to you...?

In public place, off the leash, and you are worried by it, either because its barking, jumping, filthy muddy or just plain aggressive, is it not counted as a nuisance if you already have a fear of dogs? Its been suggested to me that you have to expect dogs to be around in public places, that the previously mentioned behaviour is just what dogs do, its my fault for being afraid and at no point should the owner be called upon to bring their dog under control and keep it far enough away that it cant touch me. This cant be true, surely? That I have to accept being bothered by a dog, that the owner of the animal is not obliged to control it, or at least try to? And that if someone is afraid of dogs it makes the owner even less obliged to control the animal?