Quote Originally Posted by Gasher View Post
Adding things like texturemap quality and texturemap filter to menus inside the game bring with it the need to restart the client executable due to these options fundamental construction. In the case of texture quality and filters there is a need to pre-process/calculate lot's of data prior to showing it on the screen. This is only one of the reasons that putting these kinds of options inside the game may confuse less tech-savvy users and make their game experience less enjoyable.
This is why you decouple the rendering engine and the game engine. Then you can restart the renderer without disrupting the client.