I would consider these people the equivalent of "primitive" - "naive" - "outsider" artists by the newest definition. People that live outside of game study that accomplish great designs without the study and formal practice of games and those mathematics that bind their design.
Many designers start this way, making up rules to go with those army men or matchbox cars we got for Christmas.... I think you can sometimes find people like that that have never heard of many modern games or game theory that have been working independently of the culture and knowledge that have created wonderful works of fantasy and imagination.
I often wonder how much more creativity is lost to those of us who embrace the conformity that knowledge brings... the world needs more Willy Wonkas.
lol this curriously sounds like me. I wouldn't throw "primitive, and naive around lightly though. I may lack experience in game design but I always find out everything I need to know. Make certain you know just what you're talking about when you are thinking about this outsider designer or steriotype.
There can be the person who is well versed in every facet of theory math technique...etc, and has no talent to do anything wonderful with the tools....mediocre. There can also be the mind that no matter what they set their mind to they create beautiful works....everything they touch turns to gold.
On the other hand, I've observed lazy designers who have some idea, not a very good one......and you never here of them again. So what! You never hear from them again.