Through technology, some people are able to produce much more than others, so inequality is inevitable unless there is a balancing force (aka taxation).
"This work is essential to the health of the population, but because of something to do with marginal economics and supply and demand and weak labor laws and class power and reserve supply of labor, I don't have to pay a proper wage, or even treat them like human beings!"
Price is not about total value provided to society but about the marginal value of one more diamond, 1 more gallon of water, 1 more janitor or 1 more programmer.
All the things every country in the world does except one.
Because it currently has 2 of those (minimum wage and a health insurance mandate) at the federal level.
Consider a fast food restaurant with one cleaner, two people at the tills, three people in the kitchen, and one manager. Remove any of them and the lines will become too long, the place will become unacceptably dirty, etc. However, none of the employees is "producing" more than any other.
The people that developed email and whatnot produced more than the people who deliver mail, etc.
Author's point is not about decrease in pay but about the social changes that came about as a result of prioritizing the outsourcing of non-core-competency work to contractors, which increased competition and had the effect of reducing effective pay.
In other words, income inequality has increased as contract work has increased, and the reason why is because a large part of social mobility is due to networking and connections, which are far stronger at companies which prefer in-sourcing compared to companies which prefer out-sourcing, since out-sourcing naturally creates an "us vs. them" dynamic at companies which is difficult to overcome.
The implied conclusion is, if market forces are biased towards out-sourcing, then the government should incentivize in-sourcing as a means of combatting inequality.
If you read through the comments, one of them points out a perhaps less popular explanation - Ms Ramos apparently does not speak English. Large quantities of low skill immigration will inevitably make life tougher for people like her. But that would not be an explanation that'd be acceptable to the Times.
Well what do you expect? Journalists write news articles, not peer-reviewed studies that obey the scientific method.
A lack of English skills would certainly contribute to social isolation within an American company, so if anything, it helps drive home the point that social isolation exacerbates income inequality. I don't think anybody is making the argument that Apple bears responsibility for giving Ms. Ramos English fluency, and it's part of the reason why there aren't easy solutions. But you can't even think about solving the problem until you can start to think about its root causes.