I don't think it's the wearing of nappies that is worthy of ridicule. You are right, it's a medical question, people who need it should wear it, and everybody else should just stfu about it. (Except perhaps in the odd case when medical conditions do come into question while assessing the fitness of a candidate to an office, especially such a high stakes and demanding one as the potus, but that's by the by).

What is chilling is the followers of Trump who try to make a virtue out of it. And ridiculous. Laughing at them is the right response because the other option is utter despair.