These principles, based on experimental science as well as common sense, opened up the power of computing to several generations
Of course much of the science was based on a mouse and keyboard interaction on a computer, not touch on mobile.
Contrary to popular belief, Apple did not invent the touch interface. In fact they had absolutely nothing to do with its early development. IBM did most of the pioneering work, showcasing it with touchscreen kiosks at the U.S. Open in the 1990s (which led to the discovery of gorilla arm syndrome). Apple blatantly lifted most of that multitouch R&D and implemented it in the iPhone (then tried to sue others for "copying" them). They didn't even make the first touchscreen "smart" phone - IBM did in 1993.
Point being, touchscreens are not some newfangled 21st century development. The old GUI operating principles were based on touchscreens as well as mouse and keyboard. Many aspects like dialog boxes, radio buttons, scrolling, etc. carry over to both types of interfaces.
This is why those interfaces work. Let's take a scrolling view for example. The traditional approach is to put a scrollbar in, and that's what most everyone was doing before the iPhone came along. The scrollbar is discoverable and it provides visual feedback. Sounds good right? Well it turns out using a scrollbar on a mobile device is a miserable experience. Swipe to scroll turned out to be the vastly superior method, and as soon as you learn to swipe (my 1 year old figured it out watching me) it is trivially easy to operate without any additional visual clutter.
Actually the scrollbar became outdated with the advent of the mouse wheel. What is not outdated however is the presence of the scrollbar - not so you can use it to scroll the page, but as a visual indicator of how far along the page you've scrolled. This makes it easy to see where in a webpage or document you are, so if you can more easily navigate back to it in the future. Like you know the recipe you want in a cookbook is about 1/3rd of the way in. Unfortunately the newest design fad seems to be eliminating this visual indicator scrollbar, or designing web pages which continuously grow longer when you reach the bottom making the scroll indicator useless. Those designers should be forced to live in an apartment building where the elevator buttons are replaced by an infinitely rotatable wheel with no markings, and they have to guess how far to spin it to get to their floor.
Same with other gestures in the iPhone.
Deleting a row in a table. You can put a button on every row to make that discoverable at the cost of high risk of accidental deletion and visual noise, or you can make rows swipe left to expose the delete function. The swipe once learned in 5 seconds is vastly superior for the rest of your lifetime using it.
I can't believe you just wrote up something about scrolling, but you missed the conflict in functionality between swipe to delete and swipe to scroll. Not to mention what happens when you're trying to tap and your finger slips making it a swipe.
That's the fundamental problem with touch interfaces. The tapping vs moving motions are not orthogonal like with a mouse (where they're registered by two separate devices entirely - button and optical sensor). Actions with severe consequences have to be redesigned to compensate for this lack of orthogonality. Every swipe may in fact have meant to have been a tap, so you need extra safeguards in place of an operation like delete, not just blithely assign it to a swipe. (Google's Android apps accomplish this by immediately bringing up the undo option if you swipe to delete.)
The standard, simple way of correcting for these occasional mis-touches is to have a Back control: Android phones have Back built into the phone as a universal control that is always available. Apple does not. Why? We donâ(TM)t know.
This is debatable. Back is not consistent in Android. You press back to get out of a menu and then press it again by accident? Whoops there goes your app.
A back swipe contained within the app is both faster to access and more logical (you can't back out of an app).
Hitting back to exit an app in Android has little consequences because Android has supported multi-tasking from the get-go. You just tap the app again or bring up the app list and tap it again, and you're right back where you were a moment ago (except for the few apps which are poorly designed and reload everything from scratch when moving from the background to the foreground). I know you iOS users are a bit unfamiliar with the concept since you only recently got real multitasking, but the problem you cite of accidentally exiting an app having severe consequences is more or less unique to older versions of iOS. Android never truly exits an app unless it runs out of memory or the user explicitly exits it. Even if you reboot the device, a lot of apps save their state so when you open them you're right where you were before.
It's totally different from delete, where something disappears and you're left wondering "how the heck do I get that to come back?" As much as I'd like to say Android's back button helps in this case, it doesn't. The back button is typically used to undo a context-changing action. So if you began composing an email and changed your mind, you could hit back and it'd leave the compose interface to drop you back to the Inbox interface (and if you're in the app's main interface, back will drop you back to the Android home screen). It's more like a web browser's back button, which takes you back a "page". The back button is not typically used to undo actions performed on data like delete.
What used to work was Android's menu button. You accidentally delete something, you tap the menu button, and undo would be one of the options. Simple, effective, and always there. But Google did some usage testing and found the menu button was rarely used, so they got rid of it. Never mind that in the few cases where you did have to use it, it was really, really helpful. Simplicity trumps all apparently.
This is where the article gets really funny. "Please don't prove us wrong with real world examples". Guess what, my parents have no end of trouble with their computer (with all of it's discoverable features) but they spend 90% of the time on the iPad and picked it up very quickly. One of the first things my mom did was the five finger grab gesture to close an app. I was concerned with the switch to iOS7, but it turns out I shouldn't have worried as despite the visual overhaul there wasn't much radically different so it didn't cause them any significant issues.
Actually that is one of the problems the article points out. With the old menu-based interfaces, hotkey shortcuts were highlighted by underlining the hotkey letter in the menu. So you could use the interface via the menu, but if you found yourself using the same menu function over and over, you could easily learn the hotkey and use that instead. There is no similar assisted learning model for touch interfaces. Everything you learn, you learn from being taught, seeing other people doing it, or by doing it by accident. There's no assistance which suggests a faster way to do something that you're doing often. (Cue Clippy...)
Your parents are probably just having an easier time with the iPad because it implements a much more limited set of features than a full-blown computer app. Not because it's somehow magically easier to learn than assisted discovery tools. Try programming a spreadsheet with its myriad of different functions. It's a helluva lot easier on a computer than a tablet or phone, because the latter devices have much more limited input options.