Why Does Apple Hate Customization On iOS?

Apple does not allow you to change the stock apps that come with the iPhone (keyboard, lock screen, notification center, Newsstand, etc., and I was wondering why. I know that they like controlling the user experience to make it "as simple as possible" but it really grinds my gears to know that I can't change the stock things that come with the phone. Don't get me wrong, I see why they do it. Certain Apple apps need to stay on the phone in order for it to work, so you shouldn't really have the need to delete them (ex weather App, Newsstand). But why can't the user decide to make something else the default app instead of always having to use Apple's app. I would like the ability to add little custom things to my phone but Apple refuses to let us do it and Jailbreaking will be a thing of the past because Apple is gonna make it so iOS is unjailbreakable come iOS 7 or 8.So has Apple commented on why they do this, or is it one of those things they won't disclose why.
A lot of Apple users are happy with their iPhones (hence Apple outselling them more and more every year) but some of their users want to customize their phone and switch to Android because they can't and Apple always plays that intuitive and innovative ***.It is innovative, and defiantly intuitive because people who use it obviously only want the basic out their phones (which again is why they sell so much). Anyway, any thoughts on why Apple does this? And no Apple bashes please! Lol

Smartphone sales globally
http://techcrunch.com/2013/02/13/gartner-huawei-takes-3rd-place-in-global-smartphone-rankings-in-q4-2012-top-two-samsung-apple-dominate-with-52-share/
"For Samsung, it's the opposite story: accelerating growth. In Q4 the Korean mobile maker's overall smartphone sales rose to 64.5 million units, up 85.3 per cent from Q4 2011.In full year 2012, Samsung accrued sales of 384.6 million mobile phones, of which just over half (53.5 per cent) were smartphone sales."
"Apple's smartphone sales hit 43.5 million units in Q4, up 22.6 per cent year-on-year. For the full year 2012, Apple sold 130 million smartphones worldwide. Gartner noted that while consumer demand for iPhones in the quarter remained strong, buyers favored the less expensive iPhone 4 and 4S models over the newer iPhone 5."
Samsung sells more than Apple in smartphones globally. And Apple is selling more iPhone4 than 5.

Apple does what Apple wants to do. It is that way over the entire product line.
They don't want anyone doing anything in the product that they don't get money to do.
That is Apple in general. What you describe is what makes Apple, Apple.
Adding: They do not believe that the ability to remove applications will sell more phones. They are probably right.

Apple's success in recent years has largely been due to its ability to design and create products that appeal to a wide variety of users, from tech enthusiasts to mainstream consumers and business users.

Other companies have tried to emulate Apple's designs and its successes, resulting in numerous MacBook Air and MacBook Pro look-alikes in recent years and various parts of the OS X design incorporated into the Windows platform. (This goes both ways: While Microsoft has copied features like Spotlight, Stickies, and Widgets, Apple cribbed the Finder sidebar and the Back and Forward buttons in Finder from Windows.)

But the iPhone has been something truly remarkable from the start; it redefined the smartphone market almost overnight upon its arrival in 2007. Having done that, however, Apple has found it increasingly difficult to stay ahead of its Android-based rivals, who have mimicked features in iOS and even moved ahead of Apple in some areas. Microsoft, on the other hand, entered the smartphone market late, leaving it far behind the competition.