Why not just fix OpenGL instead? Actually, it was fixed, but no-one knows how to use OpenGL 4 yet.
In other words, it would have to become a lot more like Direct3D.
"Fixing" OpenGL to bring it into the current era of graphics development usually means making it look more like Direct3D anyway, so why not just go whole hog and adopt Direct3D?
You can't use that on the iOS devices, Android devices, OS X, Linux/Unix systems, PS3/PS4, Wii etc.
Only the PS3 has some OpenGL API support, but it is so bad most studios use libcgm, the lower level API.