No restrictions on field of use
Both Free Software and "open source" require that there be no restrictions on field of use in which software is applied.
This is an extremely controversial rule that is not followed in the Creative Commons parametric license regime, although it is an option. The CC-by-nc-sa in particular does restrict and prevent commercial use - accordingly Common Content need not be "free" by the definition in use by the ideologists at Debian or any other nerd group more interested in technology than in values.
See problems with free software and open source models for related problems that are solved or at least addressed as options in the Creative Commons Public Licenses.