Physical sharing is inherently limited. You can only share with some many friends, burn so many CD copies.

Purely digital files are so cheap to copy that cost is negligible.

Recreating “physical share” functionality in digital space takes work ($$) for $company and directly leads to less sales.

I think a good moral reasoning would be to think of it like ticket sales. You pay to get in. The event organizers take on risk and expense to run the show. Rebroadcasting is like sneaking people in.