[golergka]

Apart from performance considerations, it's also because in game development, different systems are much more entangled together in the requirements themselves, in many very small and unpredictable ways that still break architectural boundaries you put in.

For a classic example, it's makes almost no sense separate model and view when you're building a real time action game, because your rendering code and your ballistics and physics work on very similar 3d meshes that are animated by the same skeleton animations and tied to the same objects.