Sometimes it can depend on where you live.
iPhones are better for CDMA users and postpaid/subsidized countries. If I returned back to Orange County next year, my next carrier update might as well be iPhone 6s and I don't even like iOS! Why? Resell value. I have a well taken care of HTC One M7 and realized it goes for $300 second-hand which is like $100 lower than a six-month older iPhone 5. And by selling iPhones, you can sell it faster while still getting a higher return for it. No average joe really knows or cares about HTC no matter how pretty they make their phones.
I don't really care for Apple or iOS but I can understand people using carrier upgrades for them. And since US is the third most populated country behind China and India, having 40% marketshare in it is enough iOS users to communicate with. If you are going to rely on a subsidized discount, you might as well get the highest priced phone out there. The annual reselling of iPhones practically pays off for the next one. Here we have Globe as a carrier and they offer this iPhone Forever Plan. All you do is turn in your iPhone from the prev year to get the newer one for free.
Since I live in a mostly prepaid/GSM-oriented country where I have two prepaid sims, Android is far more cost efficient. It just seems more universal. It uses more universal standards like micro-sd and micro-usb. You can Bluetooth transfer to other brands even to old Symbian phones. Some Androids have analog TV, FM radio, & dual sim. Android makes alot more sense for me here. But iPhones and to some extent Galaxy Notes makes alot more sense in the US, Japan, and South Korea if CDMA is the more dominant standard, people rely on subsidized discounts, and have only one line or smartphone to use.