system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why openGL is not preferred by game developers?

Based on my assumption that openGL works on many platforms while DirectX is Windows specific.
gpt
A factor here is that Microsoft integrates DirectX development environments *deeply* into their software.  They also aggressively place their development environments into computer science programs across the United States (and perhaps elsewhere).  A huge proportion of students 'cut their teeth' on Microsoft products which are constructed to make DirectX look familiar, supported, and natural, and OpenGL as...well, not any of that.

MS also funds tool creation that is synergistic with DirectX; they invest heavily in the ecosystem.