There are other smartphones that fulfill the same purposes (that you outlined above) which are much cheaper.
If someone in poverty buys an iPhone instead of a budget alternative, it's an indicator that they lack a basic ability to evaluate a handful of economic choices and choose the most appropriate (and thrifty) one. It's the smartphone equivalent of getting chrome rims on your car wheels.
EDIT: I was disappointed but not surprised that the article didn't even acknowledge this fact, nor really make a case at all for what it was saying. I couldn't find any attempt to convince at all in what was written; it was simply a declaration of how right the author's view is and how obviously stupidly wrong the concept of someone being responsible for their own outcomes is.