That's a very good question.
It's because the distribution patterns are now changing. We're right in the midst of change. Digital copies look wonderful, and so our work is now widely distributed. What we're really talking about today is copies.
We get a revenue stream from our work and the different forms of exploitation in terms of primary use. If it's in the theatre, or if it's being sold as a TV box set, we get a royalty under our collective agreements, but what we're talking about is compensation for copying our work. For example, proposed section 29.22, if it goes unamended, would allow an unspecified number of copies of our work out into the marketplace, and unless there is some form of compensation regime attached to that through collective licensing, there is no money coming back to the creator. Even if there were a collective licensing addressed in relation to that copying, we couldn't determine who would collect it, because we haven't addressed authorship of the audiovisual work. It's as though we're four steps behind. I can say that most countries in the world addressed this issue a very long time ago.
Just to throw in one last thing, in the U.S. the studios are the copyright holders, and that's because they are the anomaly in the world. They are the complete exception in that the studios have the copyright, but in the rest of the world, authorship is a creator position.