I'm not really schizophrenic though, as a baseline. I'm a schizoid, samish name quite different workings.
I do get kinda schizophrenish like when I have manic episodes though. Happens when under too much emotional or conceptual stress. Usually get it all out on paper or file though. Got boatloads of paper and file from all past episodes. A fair share is jumbled because I couldn't focus long enough on one thing to describe in enough detail. Hard to know what will be obvious or not when you come down to earth again. Figured last time that I could try sharing a toy idea that can't really hurt anyone, on here for fun, since I've never shared before.
But on the why, I figure it's because when you're already that far out and cut off from normative thinking, you're literally thinking outside the box. You don't have to step out of it, it's the other way around. You have to step inside the box to shape it in such a way that you can actually use it. Which is why most productive cases can speak at least somewhat coherently. Though most often there is something that kinda tips you off, and if they're a case that never comes down, they usually can't really focus on one subject enough to actually explain how it works.
Like I only fly up there every once in a while, and then all the scrap thoughts come through with the usable parts. But then when I come down I function like most others on a surface level, though I have an interesting mental life. Haven't had the motivation to actually use it though, because the current way of things "work". Even though they're inefficient and primal.
Like how we've become so dependent on tools that we've forgotten how powerful a mind can be. How much a brain can store. How you don't actually need anything to prototype with if you build it inside of you, like Tesla did. Fantasy can be used for more than imagining boobs if you only realise that, and you learn to use it again. Because filling a brain with so much preformed fantasy breaks the machine that can create them, and much of my prior mental capabilites as a child are scrawny because of that. Spending so many days letting the machine corrode and rust, feeding the fear of boredom instead with so many movies and games. Music and books feed the imagination though, they inspire. You have to imagine the words yourself.
I'll attach reference to how Tesla worked. Then think how much easier it is to imagine code, words, than to imagine rotations and magnetic fields of machines. Then think how a schizophrenic can imagine the most incomprihensible things to a normative mind. That's why schizophrenics can code well, if they have the interest and ability to focus at least long enough to put it into coherent file.
A mind is also the safest place to host an artificial intelligence. Because the host will always have the last word.