My personal experience has been that while there definitely is something to be said for the innocence and originality of someone who has not been trained, they still can stumble across the same old conventions without even knowing.
We all hear conventional music from the time we are born and resisting conventions can actually be hard, even for those who are uninitiated standard music theory.
I resisted learning theory for a long time because I didn’t want to become trapped in it or overly influenced. But after learning music theory, I found that I was in a better position to understand just what it was about my compositions that were not experimental at all. Essentially, I think it is good to know your “enemy”.
That said, I’ve liked music from outsiders and rebellious insiders as well.