Sorry but none of this makes any sense at all now.
Let's define some things first.
OpenGL is a low-level API for providing 3D graphics functionality.
Direct3D is a low-level API for providing 3D graphics functionality.
DirectX is a bunch of different libraries which are shipped together.
D3DX is a supplementary library for Direct3D that provides some additional higher-level functionality.
OK, so what you can see from these is that
OpenGL is directly comparable to
Direct3D.
Not DirectX,
not D3DX,
just Direct3D
only. So it doesn't even make sense to talk about wanting features in "DirectX" to also be in OpenGL, because "DirectX" also includes sound, input, networking, setup and other things.
So first of all, please limit the scope of your request to something that it actually makes sense to compare; i.e. OpenGL and Direct3D.
Now look at the specific things that you're asking for: higher-level model and image format handling routines. Are these in Direct3D? No, they're not. They're in D3DX. Is D3DX part of DirectX? Yes, it is. Is D3DX part of Direct3D? No, it is not.
Let's see what Microsoft have to say on the matter:
http://msdn.microsoft.com/en-us/libr...=vs.85%29.aspx
And:
http://msdn.microsoft.com/en-us/libr...=vs.85%29.aspx
So even Microsoft agree here - "D3DX is a utility library that provides helper services" - not a core part of the API, helper services.
The same applies to OpenGL. This functionality does not belong in the core API, it belongs in a utility library that provides helper services.