The first difficult part of a Stack Overflow clone is to get an initial community of experts. Joel and Jeff had both a well known blogs where they can got people to form the initial community. (HN was created from the readers of the pg blog^H^H^H^H essays.)

The second problem is moderation, that is not an easy task.

My guess is that they can keep the homeopathy folks away, but I'm worry that it will be difficult to filter other stuff like the EmDrive.

And using a crytocoin instead of worthless internet points will solve none of these problems.