Bought the 1st iPhone in 2007 because there was no other phone like it back then. Not to mention the huge amount of craze about it.
I started with an iPod touch. Natural progression. There was nothing compelling enough when I bought it to consider other options.
There are more subtle reasons too: like first party support. Have a problem? Go to the Apple store. Chances are, especially if it's a defect, you're leaving THAT DAY with the problem solved. There is NO other phone out there with the support network Apple has.
ease of use
Ecosystem
I support American companies
Build quality
Features
What the heck? Aside of the fact, that the closest Apple Store is a two hour international flight away, I can take a defect $0.20 cigarrette lighter to the store I got it from and get a new one on the spot, not just if I got lucky. The thought of having to take my chances with a phone does definitely not sound like a selling feature. Actually, that sounds like absolutely horrible customer service.
Or maybe I didn't quite understand what you are trying to say?
I'm using both the Note 4 and iphone 6. I'm still thinking which device should go back. I'm more and more prefer the iPhone now but mainly because I've used android for 2 years so I need something new. The big advantage of ios is the app store. So many quality apps. Also push email/ message on iphone is FAST. I receive them instantly even faster than on computer. On Android there's a delay about 10s - 1 min.
Back in 2010 I would always carry around my iPod and flipphone and decided that only carrying one device would be much more convenient so I bought the iPhone 4.