IMO- it's that it's not a job but a skill. And that skill is meant to do a job with it, not be a job itself.

Programming ability today is like a modern equivalent of literacy or numeracy, but it's being abstractly used by the illiterate and innumerate to accomplish a job they want done but can't do themselves.

Which is how we end up with products developed by people who don't eat their own dog food. It's not necessarily their fault, it's the nature of the beast.