From the FAQ: "If you find yourself returning to check on issues, or review answers to questions others ask, or download updates to the source code, you are still using the project and need to pay the Maintenance Fee."
If I can't pull updates to the open source code then it's not open source.
> Free software” means software that respects users' freedom and community. Roughly, it means that the users have the freedom to run, copy, distribute, study, change and improve the software. Thus, “free software” is a matter of liberty, not price.
> ...
> You may have paid money to get copies of a free program, or you may have obtained copies at no charge. But regardless of how you got your copies, you always have the freedom to copy and change the software, even to sell copies.
- https://www.gnu.org/philosophy/free-sw.en.html
And the OSI applies to the "Open Source Software", aka the source code. The OSI does not apply to the "Open Source Project", aka the issue tracker, discussion forums, downloadable binaries (although the source code to recreate those binaries often needs to be available), etc.
In the end, the Software (the source code) must be free. But the time and effort of the maintainers keeping the Project running is not free. So, those consumers that make money are required to pay to keep the Project running. Or, they can choose not pay the Fee, not use the Project, and only use the Software.
The example EULA contains text like:
> Failure to pay the Fee will result in the termination of this license. Upon termination, User must cease all use of the Software and remove it from all systems.
That directly contradicts what you're saying: that the software maybe use without payment, and only participation in the project (such as using the bug tracker) requires commercial users to pay a fee.
FOSS must not have anything resembling an EULA. Give me money or erase the software is just not free open source by any stretch of the imagination.
Everything recommended by the site is OK to do, and well within an author's right. What's wrong is the misinformation that the result is still open source.