The Usability Analysts and Graphic Designers

People from all over the world assume an Usability Expert is nothing but a Graphic Artist, but its not always the case. Yes, a Graphic designer can himself be an Usability Analyst.
Whenever I got a chance to talk to Not-From-Usability-Field people, I have always seen them wrongly interpret an Usability professional being a Graphic designer.
A Graphic Designer see any product/web application from the designing point of view that contains good amount of images/flash and other multimedia, on the other hand an Usability expert won't look at any product/website just by himself, but put himself in the targeted user's shoes and then look at the application and check how user friendly the product is.
One good article from AListApart.com says Usability experts are from Mars and Graphic Designers are from Venus
The author has nicely put down equations to explain the topic, like:
Usability/Information Architecture == the masculine == the left side of the brain == doing == math/science == the rational == logical action == the articulatable == Mars.
Graphic Design == the feminine == the right side of the brain == being == art == the emotional == intuitive action == the inarticulatable == Venus.