You want to know why?
Go down the street and ask the first 100 people you come to if they know what "rooting your phone" means and watch their faces.
You are not the norm. You are not the typical consumer. You are not everyone. The notion of a phone being good because you can root it and spend time customizing and tweaking every little part of it or expand what it can do is only an appealing and interesting concept for people who would desire to do such things, and the reality is that is not everyone. This isn't some kind of new argument either; it's just a rehashing of history. The same kind of argument was occurring back in the late 90's, early 2000's, with PDA's. PocketPC's could do so much more, customize so much more, allow for so much more than Palm devices; and yet Palm dominated at the time. As a gadget freak techie kid, I couldn't understand it. Why couldn't these heathens, whom I was clearly so much better than that it made sense for me to call them derogatory names because it made me look SOOOOO smart, clearly see that because my device could be tweaked and hacked to do more than it was infinitely superior!
The answer was because I was an ignorant, self absorbed, elistist ass (i.e. a teenager) who couldn't understand that Joe Dad or John CEO or Jill Smallbusiness didn't necessarily WANT to spend hours digging around techie PDA forums as if it was a form of entertainment. They didn't want to have to understand to some degree the innerworkings of their device to get the most out of what it could do. They didn't want to spend long bits of time tweaking their PDA until it was just the way they wanted...for a day, before more tweaking occur. They didn't care if it couldn't do A, B, C, D, E, F, and G. They cared if they could open it up and easily understand it. They cared if they could start it up and figure it out easily. They cared if it worked similarly to the palm pilot they had before. They cared that it could do X, Y, and Z well because that's what they needed.
"OMG! you fools! you sheeple! don't you realize you could do SOOOOOO much more"
Yes, some of them do. No, others don't; because they have little to no need or use to do such so have never even given it much of a thought to go looking. Three years ago only about a quarter of Android users even DID root their phones (many of them doing so just to remove bloatware like "touchwiz"), and it had been trending down. Rooting isn't the norm, and there's a significant amount of "sheeple" out there that are missing out on that experience just as much while holding onto an android phone as holding onto an iPhone one. What you're talking about isn't actually an android vs apple thing; it's just a techie vs non-techie one.