Amazon has no bad influence. It will only try to sell stuff. And if somebody
can't refrain from buying a good offer that person is either perfectly human
or too childish in reasoning. Either way, that is not a sign Amazon is bad.
Amazon can be bad because it has quite a lot of information about somebody.
Like Facebook. Or Google. And it can sell that information.
A doctor buying a medical book, that is nothing special. Someone interested
in self-help books, that is also uninteresting. And it can be gathered from
other places too.
I thought the idea was to buy from stores that respect a certain common
sense. In the way one does vote with own money every day. Buying from a
reseller just means to pay for a third party just to hold your religious
views. And in this particular case, this borders hypocrisy.