In Silicon Valley? I've observed that the H-1Bs in Silicon Valley are extraordinarily high skill while the Infosys bodyshoppers are out in Des Moines and Cleveland.
Microsoft isn't even trying to directly make money off GitHub Enterprise. What they're doing is plugging GitHub into a giant ecosystem of Azure-related services that they sell to large corporations for millions of dollars per year per customer. They could give away GitHub for free entirely, and might, if there's a one-click "deploy to Azure" and similar functionality that brings people into the Microsoft shop.