This is a regression from Unity 4.2.2f1. When Unity editor is started without any flags, or with "-force-d3d11" flag, the "Edit -> Graphics Emulation -> OpenGL ES 2.0" option is available and is selected. If the "-force-opengl" flag is used, the "Edit -> Graphics Emulation -> OpenGL ES 2.0" option is grayed-out, it is impossible to select it and "No Emulation" is selected instead.

Reproduced with:
Unity Version 4.3.3f1 (c8ca9b6b9936)
Unity Version 4.3.2f1 (0517a5ae8669)
Unity Version 4.3.1f1 (cebd4d9b5122)
Unity Version 4.3.0f4 (e01000627d60)

Reproduction steps:
1. Run Unity editor with the "-force-opengl" flag
2. Open any project
3. Notice that "Edit -> Graphics Emulation -> OpenGL ES 2.0" option is grayed-out and it is impossible to select it