Well I’m reasonably sure he didn’t only sell one copy 
Also this million or billion dollar company has to employ and pay tens of tousands of people as well as premises, equipment, heinous internal burocracy etc etc.
In the end it does not matter how big a company is Both multimillion dollar companies as well as small devs have to find their own way of making it work for them - or not.
If you’re doing it as a sideline you don’t have to live of it and from experience I can tell you that many updates due to newly arising incompabilities are mere trifles. It’s not as if you have to start from scratch.
In the end it has shown that most companies and developers who don’t go with the flow of the sim will sooner or later have either a tarnished reputation or will vanish altogether. The last 20 years has seen many come and go.
Microsoft is the top dog here and all the devs including Asobo are dependent on them. But still MS isn’t forcing anyone to do anything. It’s an open system and you don’t even need permission or a license to make addons and sell them.
Microsoft only provide a platform like DCS. And if a new DCS update breaks an IndiaFoxTecho plane, Dino fixes it. And I’m reasonably sure he doesn’t complain about Eagle Dynamics
So in turn of course Microsoft won’t be responsible for thousands of addons and mods they neither had any hand in developing nor earned any money from (apart from the Marketplace kickback which is a fee for providing the sales platform like on simmarket or Orbx, who als take kickbacks).
That’s how the system works and if a dev isn’t ready to accept this, he will have to deal with the fallout alone.
Wanting it any other way is beyond reality and totally naive.