One of the reasons it likely persists is that people don't have a good understanding of what their brain does on a day-to-day basis, and they don't have a good idea of just how hard some of those tasks are.
We do things like walk across a room and pick up an object, and don't really think about all the processing that goes into that.
You have an accurate and dynamic mental model of the room, your body, and how it can function. You do an enormous amount of processing just to see and recognize anything. And it (usually) "just works" and we don't have any real insight into ourselves for how it works, for how much processing effort goes into it all.
If you have someone start down the path of programming a robot to do that "simple" task, they'll have a much greater appreciation for all the things their brain does for them. Trying to precisely coordinate the actions of tens to hundreds of muscles, receiving an enormous amount of raw sensor input (the feel of the floor under your feet, etc.) that is then filtered and prioritized for high-level consumption, all the motion planning to dodge the chair in your way, etc.
We do so much for such a simple, everyday action, that it seems "easy" and "simple" when it is nothing of the kind.
That's what that "other 90%" of your brain does, you just aren't conscious of it.