They’re not wrong, though?

Almost all information that currently exists has been created in the last century or so. Only a fraction of all that information is available to be legally acquired for use and only a fraction of that already small fraction has been explicitly licensed using permissive licenses.

Things that we don’t even think about as “protected works” are in fact just that. Doesn’t matter what it is: napkin doodles, writings on bathrooms stall walls, letters written to friends and family. All of those things are protected, unless stated otherwise. And, I don’t know about you, but I’ve never seen a license notice attached to a napkin doodle.

Now, imagine trying to raise a child while avoiding every piece of information like that; information that you aren’t licensed to use. You wouldn’t end up with a person well suited to exist in the world. They’d lack education regarding science, technology, they’d lack understanding of pop-culture, they’d know no brand names, etc.

Machine learning models are similar. You can train them that way, sure, but they’d be basically useless for real-world applications.