Maybe the people who are actually working for themselves are those who do not need people or to satisfy any customer to make profit, example like the traders who do not need to lure customers to their shop like business owners or hotel owners, or taxi owner that need to follow instructions from their clients etc.
What could be the real definition of working for yourself?
Of course they are working for themselves because they don't have anyone bossing them around so they are the direct person's to their customers unlike some employers that got employee that works under their orders. It doesn't seem the way you're thinking cause everyone needs a customer audience for their business or job be it an employer or employee. So working for yourself means you're in charge and a direct playlist to your customers.