It's not really that simple. First of all, from the article:
"It costs only US$6.50 per unit to assemble all parts and components into a ready to use iPhone. The assembly cost accounts for merely 3.6% of the total manufacturing cost."
So the Chinese company assembles (not produces) units for $6.50 a piece, which is only a tiny fraction of the total manufacturing cost. The other $180.55 of the cost of manufacturing comes largely from American countries.
And no, the article is not saying it's unfair that we can't take that last $7. In fact, just the opposite. It's lamenting the fact that most trade deficit calculations use the entire manufacturing cost (~$190 in this case) rather than just taking into account the value added ($6.50) by the exporting country. Calculating the figure this way makes the situation seem much more dire than it actually is, which results in extremist cries for a trade war. The author of this paper seems to think the $7 of value added by China is perfectly fair, and he's just trying to get others to realize that this figure is more accurate and applicable than the standard calculation.
Only a small fraction of the parts in an iPhone come from America -- the majority come from Taiwan, Japan, China and 3 other countries. So yes, China probably gets more of the entire manufacturing cost of the iPhone than the US does. But not by much. The US, of course, should be able to book that sweet sweet margin of profit that Apple enjoys. (Or should the Bermuda tax haven Apple presumably employs book the profit?)
Electronics assembly in china is also done in an "air conditioned" environment, FWIW. Has to be, or the products wouldn't work well. The iPhone is undoubtedly assembled in a room which is controlled for temperature, humidity, and dust at least as well as the offices in cupertino. Well-lit, too.
In terms of physical facilities, it is an awesome place to work. Especially by local standards. The only thing that really sucks about it by western standards is the pay and the hours. And that it's, you know, located in an industrial part of southern China. The weather is much nicer in Cupertino, and when you're at HOME (or in the communal dorms on-site) the air conditioning in Dongguan is going to suck because outside the factory there's no backup diesel generator for when you get a brownout or blackout. Which happens a couple times a day. (or did about ten years ago when I was there last)
Designers want to design; Cupertino might be the best place for that unless what you're designing is the production process. But if factory work there paid anything like a western wage it'd be a pretty attractive option for factory workers here. Although it might be hard if you don't speak Mandarin and Cantonese - I had a translator.
The article is complaining that the statistics don't reflect the reality you described. In reality, America gets most of the benefit of an iPhone sale. But in international statistics, it appears as a $500 export from China to the US, which is obvious nonsense.
1. American company creates a design in an air conditioned office in CA.
2. The Chinese company produces units from that design for <$7 a piece under relatively terrible working conditions.
3. The American company then sells the completed devices for hundreds of dollars taking pretty much all the margin for themselves.
It sounds like we are already the benefactors of the current arrangement.
The article is lamenting about how unfair it is to America because we can't take that last $7 off the table? Even I'd call that greedy.