Thanks rotorhead for the tip! That one should also clear up the problem of the p51 gunsmoke killing FPS and making the controls sluggish.
Not everybody has a dev level workstation to play a new game on. Granted, the devs need to assure that a game works reliably and smoothly on a broad target of systems. If that means cutting out effects and only rendering triangles, then that's all there is to it.
Which symptom breaks realism more, not seeing something that might occur in real life in a video game, or not being able to play a video game fluidly because of low FPS?