Just call them ignorant and move on, don't waste your time with that type of people. My brother sometimes still says that I'm not really a stutterer and I just let him know how ignorant he is and carry on. It can sometimes hurt, but don't think much about it; people who worry more about the life of others instead of their own have nothing good to say or to do, so it's really just a waste of time to waste your time with them. Keep smiling.