The reason for this from what I have observed so far is, people are not willing to accept that an expert in a specific field is supposed to know more than them. No one needs to have knowledge in every field. So a lot of people giving out ""medical information"" without really understanding in depth what they are saying.
You know that saying in bengali "অল্প বিদ্যা ভয়ংকর" That's exactly what's happening here. They are seemingly approaching with logic, but because their basic understanding of the topic has huge gaps, their logic is often flawed. And when a flawed logic arises from lack of knowledge and in depth understanding of the concept, it's quite difficult no matter how much you try and debunk the pseudoscience.