This isn't an Android vs Apple post... but seriously? Again? HBO did it like a fool. This shows how out of touch the executives are. The people a streaming services most benefits are the cord-cutters. They seem to get that much at least. But do the math of how many cord-cutters are Apple device users. People cut the cord because they don't want to pay for overpriced garbage - they are probably not users of Apple devices, because they know they can get the same or better for less by using Android. The simple fact is, most of the mobile devices on the planet run Android. So by partnering with Apple (at least at first) you are limiting your audience by a very large margin. I haven't done any research, but I would also wager that there are more non-Apple devices in home living rooms than there are Apple devices (Roku, Chromecast, Xbox, PS3/PS4 etc combined must be more than Apple TV). If you are going to "copy" the Netflix model, then do it right - release apps to access your streaming service on every platform. Netflix still supports the Wii app, and Hulu and Amazon do too. This idea of releasing to Apple devices only (at first) is just falling flat right out the gate. HBO could have made a lot of bank if they released HBO Now for Android prior to this season of Game of Thrones and Silicon Valley. They won't see a spike in subscriptions for another ~42 weeks.
I guess another way of putting it is..... there are hordes of people just ready to put money directly in to the pockets of HBO and Showtime, and they are like.... nope, nope.. we ain't gonna take your money because Apple.