Did you read the article. The workers are not extremely low income workers. They are better off than average for where they live. That is a perfectly valid point in the same way that I would not accept the pay I get in Florida for the same exact job were I living in D.C. or New york City.
And most factory workers are paid less in the US than in Europe, and outcry over that isn't very loud.
But it's a bit of a false dichotomy if someone's demanding (or rebutting) an increase of the wage to that of your own nation. If you're expecting that magically Apple would make it so that everyone at Foxconn producing ipads and iphones would get a salary of an average US worker, then you're clearly out of your mind. But then, pundits assuming that this is the only option also are quite a bit on the hyperbolic side with their argument.
The reason why Apple is getting some backlash on that – apart from basic envy – is that they're considered a premium brand. You know that you pay more just for the design – maybe even eco-friendliness. So couldn't a bit of that premium margin also be redirected towards Chinese workers? (Or maybe even a slight increase in prices to make that possible) Some kind of "fair trade" deal.
Never mind that Apple might actually be doing that, as I really don't know whether "their" workers earn more than (or are actually different from) workers assembling Dell laptops and Nokia phones.
If not, I wonder whether this could work out. If at all, it's company like Apple that could pull it off. Considering that you're already paying a pretty good price, a few dollars more going towards that end is simply a lower percentage than with bargain products.