>since iOS was not built from top-to-bottom for multi-tasking functionality...
before realizing that the author is just trolling.
iOS supported multi-tasking from day 1 -- it was a stripped-down Mac OS X, after all. They intentionally restricted multi-tasking to avoid performance and battery-life issues, a trade-off which is still paying dividends in their UX.
Apple forces developers to ask themselves, "do I really need multi-tasking?" Often the answer is "no," and the user benefits from that conversation.
Do not forget, that Apple has attitude "users do not know what they want, they will take what we offer". You don't know, whether users would be better off with multitasking or not, because you can't compare these two scenarios.
Sure, you don't need multitasking for checking in with Foursquare. You pretty much need for Location or Tasker. IOS users are not aware, that such applications exists and they are not missing them. If they would be used to them, they would miss it. Same with Swype and other apps available on Android.
Not being an insider, it might be true that no one at Android inc was talking about touch screens before 2007. But probably not. Ultimately, we can't observe what we really want to talk about here -- what would have happened without iOS.
The same compassion can go both ways; here is a link to one of many "iOS after Android" articles: http://techthirst.com/?p=414