Programmers is not the only profession that has a high cost of context switching. Scientists, lawyers, engineers, writers - pretty much anyone doing intellectual work would understand.
Now let's look back at the list provided:
-Scientists
-lawyers
-engineers
-artists
-doctors
-nurses
And compare it to programmers and writers. The non-programmer/non-writer world think programmers "just play on the computer" all day. So I think GP is spot on, non-programmers don't get how interrupting flow is catastrophic to what we do.