I think what we have to remember in the game is coding, graphics intensity, and overall performance of the game.
Right now if you watch a replay.. at a particular speed the prop no longer is a solid and visible item in the game. It becomes an almost invisible rotating haze. The prop is no longer a solid "physical" object.
I am willing to bet that in order for them to do what many of you are asking they would need to solidify the prop at least a bit which means your PC would constantly be having to graphically display at solid object rotating at thousands of RPM...
This is obviously only my observation.. as simply watching the replays does not include seeing the actual coding on the prop itself as it stands now, by I am willing to bet I am somewhere close in my statement to the truth.