Tell them not to touch the Ragdoll or go near him. He feels that his territory is being invaded. Cats need space. He may warm up to them in time. He may not. He's a cat. You can't totally control him. Cats, however, often take their cues from you. If you want him to like them he needs to see that behavior modeled from you. My cat, Mossy Grey, does not care for children, but she has come to tolerate them. Sometimes I will hold her and have a child approach her and if I feel the timing is right, i will have the child gently stroke her. Things have gotten better over time. I hope they will for you as well.