The villains in comic books usually have grandiose master plans, like targeting and defeating an enemy or ruling the world. Netflix, as it's grown to become more and more of a major player in the modern TV universe, has grand plans of its own.
Netflix started out, and took root and blossomed, by providing easy access to many of the movies and TV shows made by others. Then it began making its own TV series and movies. As those programs have succeeded wildly (starting with House of Cards) Netflix has gone all in on the original production front, to the point where it's now carpet-bombing Netflix subscribers with several new offerings a week.
Meanwhile, other entertainment companies, such as CBS and Disney, are getting into the streaming business with their own services, and beginning to withhold their product from Netflix and other distributors.
That's why original programs are so important to the future of Netflix, Amazon, Hulu and other such companies. It's also why Netflix, most aggressively, is making new series deals with David Letterman and current ABC producer superstar Shonda Rhimes — and why it partnered with Marvel Comics so boldly, and with such long-range commitment, years ago.
Netflix's plan with Marvel, from the start, was to take relatively minor or underused titles and heroes from the Marvel comic books, and star them in their own season-long TV series. Then, after that, to feature them together in The Defenders, in an all-star superhero team-up.