I get the impression that it was put in to muffle the sound of the intake system to make the noise nazis happy. From what I hear, desnorkling a stock bike doesn't seem to make much difference in performance one way or the other, but the sound level increases. BUT, when you open up the far end of the system with modified pipes, there is a substantial power increase when the rubber bits are ripped out.

Let's hope there's intelligent life somewhere in space 'cause it's buggar all down here. -- Monte Python