Monks copying texts would be a lot more interruptible than the kind of creative intellectual work that programmers do.
I agree that context switching and interruption has a high cost, but isn't the cost pretty much the same regardless of your job?
I'll admit that trivial CRUD applications are boring, but with that kind of application it's about understanding and shaping the domain. Naming things, if you will. (disclaimer: I'm working on a CRUD app as we speak, thousands of fields in dozens of modules).
also, what does original work mean? If you mean in the sense of PhD level research, I haven't worked in a lot of places where 'original work' was done. it is mostly glueing together other people's work (which is original to the person doing the glueing maybe).