Because their streaming selection blows besides a subset of TV shows and only bargain bin movies when you're looking for more obscure stuff. The whole point of online inventory is for the long tail, and they fail to deliver on that.
For example, two of the best TV shows I've seen last year were Utopia (UK) and Gomorra (Italy). They have neither and no plans to carry them anytime soon. Though if you are a Netflix UK subscriber, you can get Season 1 of Utopia and that's it. Fuck you if you live in the US: you're screwed for getting access to either season.
So it's that and that they position themselves as liberating people from the old media when it's just "Meet the new boss, same as the old boss."
So I hope they burn in hell. And they surely will be replaced only by the next pretender to rise and proclaim that they're better and different and will redeem us from previous media company abuses.
Lather, rinse, repeat.