The link is completely irrelevant to the topic. The topic is libre software versus proprietary. The link defends paid software against gratis, or at least misleadingly conflates both aspects.
That's another of these developers who benefited greatly from FLOSS, yet write condescending posts. Ironically, the author of fman makes use of Qt, which is a great example of how to make a business and still have a copyleft licensed codebase.
My problem isn't with you writing proprietary software, (I'd prefer if it wasn't proprietary, but do you as you wish). My problem is with you people who benefit daily from FLOSS to then act as if the FLOSS people are just crazy hippie, commie lunatics and how you couldn't possibly be FLOSS without also putting food on the table and how other people are apparently not (gosh!) allowed to advocate for not using proprietary software, or how is wrong for them to do so and other such garbage.
I don't care about FLOSS people. Actually, I'm grateful to them and I also have my own set of FLOSS libraries [1], because I feel we as a dev community should work together and not have to reinvent the wheel all the time. What I take issue with is being criticized for writing proprietary software. It happens somewhat regularly. And the silencing that takes place is simply unacceptable.
As I said, it has a small part mentioning open source, which is still completely irrelevant with its weak argument. I'm not sure what the author is getting at, but it seems they treat open source as gratis, which comes back to the fact that gratis is not the topic here.