What do you mean by outsider art?.
In a nutshell it is exactly what it sounds like. Those who create art outside of established norms. They are generally untrained. Not possessing any of the talents one might expect. Their point of views are often being transmitted from the fringe. Frequently, outsider art is often thought to be created by those with certifiable mental illness, but this is more a stereotype of the movement than a hard and fast rule.
The value in looking at any artworks worth outside of the established criteria of what constitutes as 'good', is that we are forced to grapple with them on the creator's terms alone. It can sometimes be almost indecipherable to us. Or, in the best cases, break open new avenues of expression, even unknowingly. But what we are looking at in all cases is the passion of an artist just blasting past the supposed requirements we think we need before we're allowed to contribute. There is liberation in this. There is also joy in knowing the unheard are finding a place to express their voice. But there also can be great beauty in these works, simply because of how personal they are to the people who've made them. It allows us into their world, which often, is one that we don't get any real vantage point into in either our day to day lives, or even the art work of others.
By its very nature, it's virtually impossible to really accurately explain the power or even worth of outsider art. For those who don't respond to it, they will dismiss it as amateurish garbage, almost immediately (and, in fairness, this is understandable). If you do like it though, it usually hits you on a very primitive, almost inarticulate level. Which is part of the joy in talking about it, because you can't reflexively go into discussion about how well it told its story, or how slick its camerawork is, or how consistent its themes are. Just like the artists themselves, we have to come from a real personal place to explain why it speaks to us. And this sort of thing appeals to me, because what I am more interested in, more than even the actual art itself, is the idea of the person that was behind creating it. Outsider art forces us to reckon with that directly because its really one of the only ways to think about it. Why does this even exist? What were they thinking? How can we begin to understand it?
Plus, outsider art has the added bonus of deeply annoying all of the people who don't like it. It's hard to ignore outsider art, once its put in front of you. This can be seen pretty clearly with something like the music of The Shaggs (probably one of the more famous examples of outsider musicians). It can't do anything but aggravate on first listen, but over time, the beauty of it might reveal itself to you. But more likely not. The key though often seems to be to remember all of the things you know art is SUPPOSED to do, and listen to how it consistently doesn't do those things. It can be a wonderful escape from having to make complete sense in in this dumb world, and it's nice that the art world allows people the space to do this.