At one time the menial jobs were done by people who were too uneducated or stupid to do anything else. Those times are gone.
However most born ins become window washers because they are happy with the "eggychashion" they get from the Asleep rag (equivalent to a college degree no less)
Most references are in threads to do with things like blood, transplants, going to college - I dont want an uneducated person advising me on life critical issues. If I need surgery or advice I go to somebody qualified to tell me what's what. It is what the word EXPERT tells us, as opposed to AMATEUR, cheese and cracker waiter, or window washer. (If I need advice on my windows or need catering I will go to a professional)
Even bible translations list the staff doing the work - not out of vanity but to assure the reader that they know what they are doing. (NOT so with NWT - how did marshmallow instead of mallow come to be in Job?)
Window washing is honorable work (my first job after university was cleaning) but most born in dubs do it instead of getting educated. NOT the same thing as doing it because you have NO CHOICE.