@nonlinear NC is a separate problem, much has been written about it.

But the tl;dr for that is that it's just unclear what it means. If a not-for-profit uses it, is it non-commercial? What if they accept donations? What if they use it in their newsletter, where they ask for donations? What if... just too many what-ifs.

Most people, when they see (and understand) NC, will just not do anything with such content at all.

Those who don't understand it will use it any way they want, including commercially.