I've used Android phones and while they are fine enough, the UI feels a little 'off' and the responsiveness is lower. It's enough to make a real, subjective difference.
I like to think that I got an iPhone after carefully considering all the alternatives and making an informed technical analysis because I am a unique individual and I would never follow the herd or copy other peoples' actions. (At least that's what I tell myself.)
You might want to think different (sic) about that for a moment, given that there are hundreds of millions of iOS devices out there in use right now.
Virtually everyone who can afford an iPhone either has one already, or has at least tried one out a bit.
Maybe 25% market penetration? Not small potatoes, but still, Most people haven't bought one.