The reason was back the days when DX8 started to support shaders but OpenGL was not even capable of using all hardware powers. It still suffers its stupid decision to make any hardware manufacturer capable of create own extensions (you can recognize them by nv_ _nv or ati_ _ati and similar) which make it more work to behave the same on all configurations.
And why mark didn't include a higher OpenGL: He did. OpenGL 1.2 is the latest. Everything above are only extensions and they are included in BM up to the extensions for OpenGL 1.5+ and that in the same way as in most apps: GLEW. You can find it under pub.glew
And why mark didn't include a higher OpenGL: He did. OpenGL 1.2 is the latest. Everything above are only extensions and they are included in BM up to the extensions for OpenGL 1.5+ and that in the same way as in most apps: GLEW. You can find it under pub.glew