Rainbird on 28 April 2009
Many of those titles require something different from their engines, and since the developers already help each other out with their engines (tech advice, stuff like that), it doesn't get much better.
Besides, it's important for the programmers to know their engine, so they can utilize it as best as possible, which is best done by constructing the engine themselves. There is a reason Epic Games are the ones pushing the Unreal engines, and not so much everyone else.
