I think their argument is with the way the algorithms work. As I understand it, when you go to YouTube, you see those "you may also be interested in" topics over on the right side of the screen. Under Bill C-11, the streamers are forced to make sure CanCon choices are prominently featured there, in what the government calls "discoverability."

The fear is that, a) it will prevent their offerings from being presented prominently there instead of 16 pages later, which no one ever gets to or b) if their content does show up and no one clicks on it, the algorithm will take that to mean no one's interested and will force it to the bottom. And while it will still be there, no one will ever scroll through all the choices to find it - including those internationally, who will never get to see it in the first place because they're not bound by our Canadian-first rules. 

I'm not 100% certain of this, but I've been told the way the algorithm works now is that similar themed topics are grouped in front of you based on the most viewed. So if you're looking for say, the unboxing videos of vintage Hot Wheels collectibles, the audience who might be interested will never find you, including international viewers if no one in Canada bothered to watch you here. 

The program will force your presentation down the list and the further down you go, ironically, the less "discoverability" you'll have around the world, Which means sponsors won't be interested in supporting you, killing the Golden Video Goose you've been relying on to make a living.  

I believe that's what they're afraid of.  

I stand open to correction if anyone has a different interpretation. But they seem to be telling the government, 'if it ain't broke, don't fix it.'

 All algorithms are artificially boosting content.  I don't really see the difference.