Direct3D solves a different problem. Direct3D insulates the developer from the direct implementation of the graphics chip so that the game transparently runs across multiple graphics chips. This is a different goal and consequently a different strategy. OpenGL is another story. OpenGL is primarily an API that only a few developers have found useful in developing games.
Game developers are a very unique set of people.
They are very technically sophisticated and simultaneously, very artistically creative. They choose a set of tools to develop the game based on their requirements of the game. If they don't mind creating a lot of the 3D-software pipeline and the goal is to dive into the details of the chip, then Glide is a good choice. Where portability is a key goal, some developers choose Direct3D or they choose both paths. Glide is optimal for a technology showcase and Direct3D, for broad support.