I don't think anyone ever questioned the right to ownership of the product of the mind until we moved into a computer age, because prior to the computer age, any product of the mind inevitably needed physical materials to be duplicated/owned, which people just took for granted and never really questioned the right to the product of the mind.
With the ease of copying reduced to copy/paste/rip, with zero raw materials used (ink,paper, printing press, etc.), there is no longer any physical loss/investment, thus leading people to question the former.
With music specifically, I think the whole purpose of the recorded music should be to get the word out about your band so people come see you perform live. But due to the vampirical nature of corporate types, the recording industry has seen this as a way to make massive amounts of money while sitting on their ass, swindling consumers and musicians alike out of their cash.
When you cut money off from a particular destination, see who hollars and you find out who is really getting it, and very few bands are complaining about downloaders. It's the labels that are complaining. Studios are complaining about ProTools, etc.
Business models change and evolve, and the titans of the old way are always going to try and claw and change laws to keep them on top.