I think reading/writing music has its place in any musical situation and can be extremely beneficial in many cases. But in terms of pop/rock music its importance isn't that great. My views on the matter are probably stronger because almost all the musicians I admire don't read/write music. None of The Beatles could read music and it hardly held them back. Crowded House, Travis, U2, etc - as far as I know don't read/write music. Sometimes something beautiful can happen when you don't really know what you're doing. You don't get caught up in seeing music as notes on a piece of paper. Its like John Lennon playing the opening chord of "Hard Day's Night" - George Martin has said to this day he still doesn't know the exact notes John played in that chord.