Because Disney aren't just competing with Netflix and co; they're also competing with usenet services, torrents, Kodi streams and other illegal services. And because Disney keep fucking their own consumers about it's left a void where the illegal services have not only been able to raise the bar in terms of user experience, but also in terms of available content and video quality.
In any other industry market forces would be in effect forcing business to either compete or go under. But because copyright laws give content owners a monopoly it means the only effective competition is illegal services. And the daft thing is they're literally better in every way. Which is why I know so many people who normally follow the letter of the law and who happily pay for expensive cable / satellite / Netflix / whatever subscriptions who also have absolutely no qualms in downloading or streaming movies illegally. These are customers who want to pay for services but end up pirating because there isn't any service available to them.
It's completely bonkers. It shouldn't be like this but it is entirely the fault of the content industry. They created the void by monopolising their content and then failing to provide any practical services. And they created the demand by targeting their advertising at kids, by making it illegal to backup old formats like DVDs, and such like.
So to answer your question, sure they can try to extract the most profit from it but customers are already angry, fed up and aware of better albeit illegal services so all Disney are going to do is drive more people to piracy. If they really wanted to extract more profit then they would trying to onboard more users instead of making their content harder to get hold of. It really feels like the whole FRAND patents situation where Disney are happy to become a critical part of pre-teen culture but don't want to licence their intellectual property in any reasonable way. And while I can happily make the decision not to watch any Disney movies again (I like Marvel but I can live without it), trying to explain that to my 3 and 6 year old is going to be much harder.