I couldn't figure out what point the article you linked to was trying to make, but the fact that pretty much everything you buy is not stamped with "Made in USA" means that the cost to make it in the US was higher than elsewhere, and presumably people would choose to not buy it.
It wasn't because there was a manager's convention and they all agreed to send the work abroad so they could have more power and control. It's because if they didn't, their competitor would have, and Walmart would have chosen to put that cheaper product on their shelves rather than yours.
Products high up on the value chain - the kind you don't dress up in your best slacks to go and buy at Walmart are a different story, however.
I can count several software projects that were outsourced off the top of my head that were ostensibly done for cost savings purposes and were utter disasters. These disasters are routinely covered up and bullshitted, too.
This has at the same time not dampened the appetite for outsourcing software much. Coordination (i.e. management) costs are higher. Consulting companies can bill millions for these projects.
This is the point the article was making - pretty cogently.
It's less of a smoke-filled room conspiracy and more of a mundane "conspiracy" to shape the supply/demand curve.
https://www.nakedcapitalism.com/2015/05/more-on-the-myth-of-...