I believe I see your point now, but I still disagree.
I know a number of self-employed people in various service industries (plumbing, decoration and such). They never say they're working at home. They do mention that their office is at home, but they say that they work on site.
People who work AT home are most likely people who do work for customers on the Internet, or who can be contacted via the Internet. Translators and such, I would venture. Those people don't work on site, I would think, or rarely. Maybe also people who build or recover furniture. They will leave home to look for new acquisitions, or to bring their wares to various selling points. They won't likely do work on site either.
Biting the hand that feeds IT
