I think you've missed their point. Those engineers are aware of the cost of context switching, and because they plan accordingly they're able to get more done than those who don't
There might be a good reason why code developed under extreme focus also tends to be inscrutable to others.
Wow. I have never thought about it this way. That's quite a profound insight. Thanks.
The corollary is true as well. I, as well as many others I imagine, have had to fix and maintain dumpster fires of spaghetti code developed under the standard distraction-filled modern business day.
Distraction doesn't beget good code; instead, a good programmer learns how to be as productive as they can despite the dysfunction of a typical modern business.