Edit: I think this engine just isnt good for 3d ego shooters. Ok, games like left4dead even run with about 30fps. But they have a gigantic map, lot of shaders, lot of pp shaders and hunderts of attacking enemys plus 3 friend-ais around u. u cant compare that.
They (Valve) had also to think about performance. You just can't have a big map the whole time in memory and let it render every frame, you have to stream the map. Having thousand of functions running every frame with their own stack is also a no go for performance.
The straightforward way of just pushing everything in the level and then blaming the engine if it fails might look easy and like a way worth going, but reality is that you have to think too. Sorry if this destroys your view of the world now.
