I upvoted you but I disagree. When designers do unsolicited "spec" redesigns of big brands, I don't think they are representing the customer.
You can't represent the customer without doing some real research with real customers. I can't remember ever seeing those sorts of results in a spec redesign post.
Instead, I think they are using the brand as a canvas to show off their own abilities. And they always pick a big popular brand, because then they can leverage that popularity to promote their work.
Andrew Kim has a great unsolicited redesign of the American Ballot system that considered users primarily and doesn't lean too heavy on using the brand as a canvas.
http://www.minimallyminimal.com/blog/america-elect
Teensy bit bland for my tastes but it goes to show there are designer out there who do some quality redesigns.
You can't represent the customer without doing some real research with real customers. I can't remember ever seeing those sorts of results in a spec redesign post.
Instead, I think they are using the brand as a canvas to show off their own abilities. And they always pick a big popular brand, because then they can leverage that popularity to promote their work.