The thing I find most bizarre about Khan Academy (which, in principal, I love) is the whacky focus on Khan. Why not crowd source the tutorials? In my opinion S

The thing I find most bizarre about Khan Academy (which, in principal, I love) is the whacky focus on Khan. Why not crowd source the tutorials? In my opinion Stack Overflow is a better model for this stuff. Imagine something like Stack Overflow focused on video tutorials covering concepts that got up voted. (heck, maybe it exists.) why can't I upload my take on "slope" (or whatever) rather than just post Q&A on Khan's?