Producing their own IP has been integral to Netflix's strategy ever since the early days when they were delivering DVDs to people. 

If they are to survive and continue to grow then they need unique content that their platform owns.  They've known Disney would launch its own streaming service for a very long time and they've been preparing for it.

They only way they will keep users from jumping ship is by supplying a steady stream of high-quality content that's been produced in-house.