Look, the iPhone 5s is actually a great device and it looks awesome. I'm genuinely impressed with what they've done here (minus the pathetic screen size). But the answer to your last question is so easy I can't believe you're asking it.
They remain #1 in customer satisfaction because even if they released a mound of dog sh** and put the Apple logo on it, they'd still be praised by the majority of their customers, The Verge, and many other tech sites. iPhone fans (kind of like Nexus fans) always say they'll buy the next version before they even know what it will contain. Their blind loyalty is astonishing to me. I would be blown away to hear an objective pro and con list of the iPhone from someone who's owned the 4, 4s, 5, and then the 5s. They just can't do it. It's the best at everything no matter what. I bet there's thousands of iPhone fans that will tell you that their NFC works better than Android's.
When my friend was asking around to get advice on what to get for a new smartphone, his iPhone fan manager told him to get an iPhone because: "It can do everything Android can, but better." Then he asked me, and I gave him a list of cons about Android FIRST, and then told him why it's still worth it to get the S3 (this was in 2012). He loves his S3 and said he didn't want the iPhone because everyone he talked to said it was the best phone available, but could NEVER tell him specifically why.
People will disagree with me (because they're fans of iPhone and therefore prove my above point) and that's okay. This is my experience that i've seen many times first hand. I love Android, but I am 80% sure I would have gotten the iPhone 5s if it had a 4.5" screen or bigger. Until then, I will stick to Android and hope that one day Apple will set their pride aside and admit that Android has something with these larger screens. At least release a big screen option and a microscopic screen option for those who still want it. Instead they release a colorful piece of shiz with the same tiny screen.