Of course, if people took a few more seconds to think about any piece of art, they would soon realise that even if they could make it, they probably wouldn't know why they were producing something without thinking very deeply about the subject and the message they wished to convey. That said, if the goal of art is to elicit a response, I suppose 'I could do that' does in itself satisfy that condition.
But even in science, psychology appears to elicit this response more than say, theoretical physics.
There are many reasons, not least that a psychology paper is far more likely to reach the mainstream media than one published in theoretical physics. Even without this, the fact remains that everyone, in some capacity, is an amateur psychologist. We can't help but try to understand ourselves and other people.
While this shouldn't come as a huge shock to the system, I remain surprised that many professional psychologists and other scientists fall into a similar pattern of behaviour and will often try to suggest that work is 'intrinsically obvious' or limited to 'folk psychology'.
The term folk psychology doesn't align itself to a scientific perspective, particularly when it comes to making conclusions about people. The average person will only know about a dozen people well (see Dunbar's number) and a few hundred in extreme cases. That prevents any form of assumption or analysis, especially when most of us only know a fairly restricted kind of person. For example, many academics know many other academics and talk about academicy type things. In a rather ironic twist of fate, scientists are, by our very nature, rather detached from the folk part of folk psychology.
Moving beyond what happens in one person's head to the influences and associations across an entire population is not possible with folk psychology, but we should also be mindful that folk psychology occupies a unique place. Folk medicine would generally not be accepted by anyone (except maybe homeopaths), but many psychologists (amateur and professional) continue to accept the notion that folk psychology provides an acceptable explanation or reason to dismiss an idea.