[nemetroid]

The author is making a statement about Discord specifically, not proprietary software in general.

[Debug_Overload]

Sure but the argument seemed to be more general. From the article:

  Perceptive readers might have noticed that most of these 
  arguments can be generalized. This article is much the same 
  if we replace “Discord” with “GitHub”, for instance, or “ 
  Twitter” or “YouTube”.