Former Netflix employee here--though I left in late 2013. I remember sitting at a company meeting and Reed Hastings explaining that AAA film content was never going to be the bread-and-butter for Netflix for several reasons. Most importantly: Between traditional, "linear" television and Netflix, the experience that Netflix brings with a combination of a low subscription cost, no commercials, and the ability to watch as many episodes of a show as you want to watch whenever you want to watch them is VASTLY superior.
Netflix survives and thrives on binge-watching--and people just don't do that with movies (they have a LOT of data to back up that statement). Combined with the realities of the costs associated with feature film licensing and there's very little incentive for Netflix to put any emphasis on films.
The only way they could do it is to tack on a pay-per-view service for films (because their subscription fee alone will absolutely NOT cover the cost of licensing more feature film content) and they are highly averse to such a service. The general feeling is that it's better for the average user if they can open up Netflix and watch whatever is there without ever thinking about whether it's an "included" title or a "PPV" title. When I was there, we regularly revisited this assumption and research always found that it continued to be the prudent move.