You'd be amazed at how many people just don't get it. I know people just like the ones described in the article who are more social butterflies, never needing to get "in the zone" as you put it (or needing to get into it much less often). For them, it's never about understanding depth, but more surface level stuff.

For me, everyday starts with a period of time (15 min to half an hour) spent just trying to get myself to get back in the flow of what I need to get done, and if I'm interrupted by, say an unplanned meeting, or an impromptu chat with my manager, then I need to start all over again! :(

When I'm in the zone, I can crunch stuff up in half or even a third of the time compared to if I'm repeatedly interrupted, but that's pretty much a nobrainer I guess

I would guess 'management' would be the more likely target. In jobs like sales and administration, being able to rapidly switch focus to what just came up is advantageous. The people on the manufacturing floor or operations I have worked with have the same issues with being interrupted during their work, though it's often an engineer that's the culprit. (Managers can quantify 'blue colar' productivity losses easier.)