And if they get a return investment, we'll see a Season 2. It's all about ratings and if enough people are watching it, Netflix will pay up because it keeps them subscribing.
Plus, separate showrunners mean that we'll get new seasons of Daredevil and Jessica Jones before Iron Fist and Luke Cage hit, provided that neither series flops.
For instance, we'l probably see Daredevil again in mid-2016, which is when Iron Fist is set to premiere, then Season 2 of Jessica Jones will hit in late 2016 a few months before Luke Cage lands in early 2017 with plot threads from Jessica Jones Season 2 being part of Luke Cage.
And in 2018, we'll get our Defenders. And by then we'll have an amazing roster of Defenders to play with. Particularly since it's possible to introduce a lot of new characters in four seasons of Daredevil, 3 seasons of Jessica Jones and 2 seasons of Iron Fist and Luke Cage.
From Daredevil: Elektra, Echo
From Jessica Jones: Hellcat
From Iron Fist: Misty Knight, Colleen Wing, Shang Chi
From Luke Cage: White Tiger
And then Doctor Strange and Spider-Man from the films, possibly also Hulk since he's heavily associated with the Defenders but I'd save Hulk for the last episode.
And Marvel still has yet to develop Moon Knight or She-Hulk who can both join the Defenders, Black Cat probably won't have appeared in the MCU Spider-Man yet, we won't have seen Namor in an Avengers sequel and Iceman, Silver Surfer and Human Torch are over at Fox so it won't be a perfect Defenders roster but it'll be close enough and there will be room to grow in case there's a Defenders 2.