They don't learn that much about science in med school. Not much different from many other college degrees.
Also they learn very little about psychology/psychiatry.
So if someone has a MD degree they should be knowledgable about the human body but that doesn't necessarily mean that they are scientists or can read scientific publications or that they are expert psychologists.
Well, no one claimed they knew anything about psychiatry... but I'm sure they have to read and interpret scientific articles as part of their training. I had to do that, and I have a MS, which at least theoretically requires less training.
Then again, as someone who is and was an instructor, their teachers can talk until they're blue in the face about logic, but some will decide it isn't important that they absorb it or learn to apply it in different situations. Many people find it more comfortable to rely on someone else's thinking, either because the process of picking something apart themselves seems like work, or they are too insecure to rely on their own conclusions.
To presume that this is
always the case, though, gives humanity too little credit. In every profession, there are people who are giving their all at their job and people who are just 'getting by'. I think the medical profession is no exception.
-J