It's a two cultures problem in IT. The vast majority of Microsoft's, or Apples, or Oracles, or whoever's customers use their OS on laptops, workstations, or servers, where the consequences of bugs are fairly well approximated by "nuisance". The other culture of computer software customers are folks who use computers handle large amounts of money and control moving machinery (power plants, drones, etc), where the consequences of bugs and unintended features start at "oh shit, we've lost millions of dollars" to "oh shit, the crane dropped its load 200ft" up through "oh God, the power plant has exploded!" People in the second camp have a healthy suspicion of getting the latest and greatest upgrade from companies run by and for people in the first camp. And that dichotomy is why most embedded OS's come with source code that you get to debug yourself if it doesn't quite work for your application (VxWorks, QNX, Windows Embedded, RTLinux, etc).