This is sort of a loaded article, since it glances over the benefits of DirectX. (Note: I'm an OpenGL developer, but I worked on implementing D3D10 on top of OpenGL, and I've worked with DX7+ over the years. I'm not a fan, but leaving these things out is misleading.)

First and foremost, it's wrong to compare OpenGL and DirectX, rather than OpenGL and Direct3D. OpenGL directly competes with a small portion of Direct3D, and requires several libraries (I'm a big fan of SDL, OpenAL, etc myself) to begin to touch the breadth of DX.

Second, with OpenGL you have many vendors producing extensions and implementing them at different times. With Direct3D, you have a single set of features you write for which are guaranteed to be there (in a given version). This means that when you write code for OpenGL, you have to special-case paths for many different available extensions and duplicate many pieces of functionality.

If you want to use shaders, you have to either make your own effects system on top of GLSL/ARB shaders or use something like Cg. The Direct3D effects pipeline saves a lot of time, but of course reduces flexibility.

In the end, the call on OGL vs DX really comes down to these things: How much do you care about cross-platform compatibility? How much time do you have to put into your engine? Do you want complete flexibility w.r.t. your rendering pipeline?

If you're an engine-tech-heavy firm, OpenGL will almost always be the right choice. If you're just making a game, DirectX will almost definitely save you time. Again, I'm not a DX fan, but it has its place, and this sort of article is woefully misleading.

The most important life lesson that I have learned that I like to share with fellow entrepreneurs who have failed in startups or friends and family members who have lost a job is the old Chinese saying that, “Grass survives the heaviest of rock.” The emphasis here is “grass”. If you put a rock on a flower, flower will die. If you put a rock on grass, grass will find a way to survive. As entrepreneurs, we are not entitled to anything. We must not think of ourselves as flowers that deserve sunshine and nutrients. We must accept that we are the lowest form of beings, or we won't find the courage and the clarity to survive. As I learned to say in America, as entrepreneurs, your ass is grass and the world is your lawnmower. So don't go looking for “love” in the wrong places. Good luck, everyone.