Amazing. I didn't know that. The lengths software people will go to avoid getting compensated for their work, eh?
So yeah, scratch the above then. You'll have to dual license with a modified license for non-commercial use. Same idea, slightly different execution (but still no need to go to GPL extremes if you don't want to).
Any non-commercial license will have to have implications similar to the GPL, and thus scare off most users, prevent projects from wanting to incur this as a dependency, and so on. It is one way to go, but will seriously limit reach. Also, as I said, it'll require contributors to sign over their rights.
So yeah, scratch the above then. You'll have to dual license with a modified license for non-commercial use. Same idea, slightly different execution (but still no need to go to GPL extremes if you don't want to).