I thought "coaching" was the answer to. I came in as a tech lead where one "developer" hired by a previous regime didn't know how to write a JavaScript function and just couldn't logically figure out how to debug an issue and the other just couldn't focus on a problem and went way out in left field on the simplest tasks.
We got rid of both of them as part of a "restructuring". I've had to cut a few contractors short because they just couldn't handle what for all intents and purposes was a startup environment where everything was up in the air and we needed people who could adapt, figure things out, and learn fast without holding their hands.
In a place like Netflix, everything is brand new. No one in history has ever had to deal with the scale that they have to.