I want to see one thing on a streaming service, but I can't afford to pay monthly for that service just to watch that one thing. I would have bought the DVD and given them some of my money, but without that option I don't get to watch that thing and they get none of my money.
I suppose overall they still get somebody's money every month, so they don't mind missing out on mine... but somehow it still feels like a step backwards for digital media.