Open Source vs Free Software is very simple
The Open Source community only cares about the Source Code, they are generally developer centrist, and generally work with "open sourcing" tools, libraries, languages and components used to build applications.
Looks on github's open source projects, what is the ratio of Full Applications, compared to libraries, tools, and components? Probably over 100 libraries, tools, and components for every 1 application
Open Source community has become a purely developer community that does not give 2 shits about the freedom of users or consumers. Most of the devs in open source today are building SaaS, PaaS and IaaS services that are closed source or non-source distributed "open source" services meaning that is perfectly legal to incorporate open source in to a SaaS product and not release the source code.
Free Software however believe all users of the software have a equal right to the source code as the developers. The recent Nest development of them closing their API is a clear example of the difference, if it was a Free Software based API I would have the ability to run my own Nest API server, but while Nest uses many open source libraries the service itself is Closed Source.
That is main compromise and divergence that happened between Free Software and Open Source.
As to making money off Free Software, I have no problems with that, it is not part of this issue. Open Source advocates like to bring that up as a red herring to divert the conversation from the primary debate. Often claiming that if they can not close their final product "they can not make any money" as an excuse why they do not support Free (Libre) software