A good example is Tech Support. The accent of some engineers is so difficult to understand that I've had to on occasion ask to speak to another engineer and I've given the reason as "I can't understand what you are saying because your accent is so pronounced".
Most people think the primary job of the programmer is pushing bits. The primary job of the programmer is understanding what the program is supposed to do and making it do that.
The actual code is usually the simplest part of the job.
A good example is Tech Support. The accent of some engineers is so difficult to understand that I've had to on occasion ask to speak to another engineer and I've given the reason as "I can't understand what you are saying because your accent is so pronounced".
If you as a user can not understand tech support that person you can not understand is effectively useless and not at all productive.