It's been a conflation issue (and major point of contention) since the 90s. "Free Software" and "Open Source Software" are two different things that have traditionally been used together to promote the rights of the user and the dissemination of knowledge in software development.

Edit, see:

https://en.wikipedia.org/wiki/The_Open_Source_Definition

https://en.wikipedia.org/wiki/The_Free_Software_Definition