You highlight a common fallacy that is repeated across the internet: "If you can't explain to me why I'm wrong, then I must be right," or something similar. But as you point out, this assumes that an explanation can be written in just a few paragraphs, which usually isn't the case. It takes years of study and experience to become an expert in a given field, and as a result, it becomes too difficult to accurately convey the necessary information to get a point across.