Amazon's M.O. is "pay money, get physical item". On the scale of how much aesthetics matters on a website, that's way over on the "not at all" side. About the only thing I'd put further that direction is Craigslist (which is "maybe pay no money, maybe get physical item").

For nearly every other website, aesthetics is of significant or even primary concern. When I'm not receiving packages from it, I care about how it looks. Facebook, Google, and StackOverflow were all much cleaner designs than what they replaced, and Wikipedia is perhaps the biggest and most aesthetically consistent website there is. Aesthetics matter.