Although I mostly skimmed the article, I have to say that the feeling I got from the article changed a couple of times between positive v. negative. This left me confused and because of that I guess I missed the point as well.
For me, the words "amazon made me thousands of dollars" in the title rather set the tone.
I don't know whether the title has changed since your comment but I fail to see how "Amazon flipped a default and made me thousands of Dollars" could ever be a negative story.
It was written in a format I'm used to seeing as "grumpy rant", mostly, and much of the language used was overwhelmingly neutral.