Because most people can't do this or even know what you mean by this sentence. There is a reason why developers exist, and it's not because they can code per se. They solve problems that people don't know how to, and the code is just a means to that end.
You're assuming the person above is a coder. The example I gave earlier was that one could start a greeting card company without hiring any artists. 'Greeting cards' traditionally have art imagery of some kind on the front. I picked this an example because it's a ~$20 billion industry which a lot f artists have sold product to until now.
