One question that came up in our discussions proved to be very interesting. We were chatting to a friend of ours, and they said, "I know you can get copies of some things for free off the net, but where did those copies come from?"
The answer seems obvious at first - usually someone owned a hard copy, scanned it and uploaded it. These are generally old and sometimes dubious editions that are out of copyright (but not always! a story for another time....)
Where did that hard copy come from though? Well at some point in time, a publisher saw enough value in the music of a composer to invest in the music by funding and organising its typesetting, printing, distribution, promotion and many, MANY other things.
And how is a venture like that made possible? Only through the support of musicians seeing enough value in the music to invest in the purchase of it so they can perform it in the first place.
So even music that on face value may seem free and easy to get can be traced back to a publisher at some point. By removing the relationship between performers and publishers, a vital link in the chain is falling away.
Publishers rely on the support of musicians in the same way that musicians rely on the support of their audiences. Publishers in turn use this support to continue THEIR vital support of composers.