And what if an open source project wants to enter this field?
For open source non-profit, it'd still be NC and therefore legal?
A key part of the Open Source Definition is that you do not lose your permission to use and copy the code based on what you do with it. A project that you aren't allowed to use anymore if you start making money from it is not Open Source.
"Non-commercial" code restrictions are more like the thing where you're allowed to look at the Windows source code, if you're an academic and you ask nicely and you won't ever do anything with it.