The correct way to say it would be there is a 2:1 ratio of content to advertising. By saying 50% of the programming is advertising you are including advertising

The correct way to say it would be there is a 2:1 ratio of content to advertising. By saying 50% of the programming is advertising you are including advertising in what you consider programming, making the statement false. This is still just nitpicking at the details, your original point is still valid.