Because they can and there is no law against it.

And really they aren't restricting any of that. I've never had Claude stop me from going to the library and reading a book.

You don't have a legal right to do anything you want with their model. And if you don't like that you are going to have to convince politicians to enact new laws to change that.

Because morons end up using Claude to write down how to plan crimes and then people get up in arms over that.