Siding with Orn on this.
Yeah, outsider art was originally used to classify art by the mentally ill and all that, but it has, well be adopted by others who are more or less perfectly mentally capable. These people have diluted the definition to pretty much mean "Anything I can slap together and label as 'ART' is art"
Yes, All beautiful things aren't art, and all art is not beautiful things. (I think thats a quote from someone,) but you gotta draw the line somewhere. It doesn't just stop at just drawing. What about that "Canned Artist's Shit" or that woman who sat on the steps of an art museum and drew really terrible portraits of folks (no really, they were like 5 year kid old drawing) She was mentally healthy, but she called it art and is listed in outsider art sections.
Again, I agree with Orn. Outsider art have become a lable for people to cop out from actually trying to learn skills to make decent art. They go for shock value or just plain stupidity now rather than actually trying. Here is another example of performance "Outsider Art" that just kind of shows the crap that i'm talking about.
I admit, the mind of the mentally ill would be a fascinating place to see, it really would. and when they sometimes do have the ability to place that mind on to paper or canvas or sculpture, it is usually interesting and intriguing. But most of the time outsider art is just hacks who are simply lazy.