People absolutely are paying for separate services. There's a limit to how many, but many, many people are paying for Netflix + HBO, or Amazon + HBO, because they believe HBO delivers value for the money. In contrast, I suspect very few people are likely to sign up for the CBS service, Star Trek or not, because I don't think many people believe CBS delivers value for the money.

Disney is banking on people believing they deliver value for the money. For parents of young children, maybe they do. Certainly more than "nobody" will agree.