Most of the time you can just buy the same thing in another place. Maybe it's different in the US but here in Europe I don't find Amazon better or faster than any random e-commerce website, so it's pretty trivial to boycott them.
In fact, I do avoid buying from them as I don't like the way they treat their employees.
I get the impression Amazon are much "bigger" in the states. Size, reach, marketing? Not sure. I don't particularly find Amazon UK very user friendly and very rarely if ever do they have the cheapest price so I don't find myself there often.
I also consider them a bit dirty for the same reason as you as I know employees and they are treated like garbage. Maybe not in head office, but certainly in distribution.
In fact, I do avoid buying from them as I don't like the way they treat their employees.