In my view, people started developing for DOS, and it became a standard for small scale and casual developers. Even into the Windows era, a lot of utilities ran

In my view, people started developing for DOS, and it became a standard for small scale and casual developers. Even into the Windows era, a lot of utilities ran under DOS, such as early embedded development tools. Programming any Windowed OS was too hard, and we had only been programming for a few years, in relative isolation from one another and beholden to crappy documentation. Especially with tools like Turbo Pascal, writing "software" that looked like commercial software was relatively easy and got the job done. Maintaining and growing any kind of platform becomes a whole new ball game when "what are its specs" is replaced by "will it run my apps?"