The last thing the world needs is to mock people for speaking up.
Actually for-real boycotting and similar types of actions like calls for coordinated divestiture do often cause changes, sometimes very big ones; but a few people posting on some internet forums is by no means a real boycott.
Personally I also have a number of issues with Amazon but none of them are serious enough to overcome the fact that they do retail sales on the Internet about a billion times better than anyone else (only Newegg comes close, and only in the narrow band of computers/electronics).
Stripe exists because they have a really awesome API and they make refunds super easy without penalties.
Square exists because Jack Dorsey is able to drum up a lot of VC money and engineering talent from followers of his personality cult. Not a lot of profitable business though, apparently.
Every other day it's someone saying they'll never use Facebook again, they'll never use Amazon again, they've quit Dropbox, they'll never use Google again. People in HN are quitting startups, quitting established companies, forswearing this and that, and getting angry at all kinds of shit day in and day out, and to be honest, I'm not sure it's ever made any bit of difference ever.
Even GoDaddy is still alive and strong and not one of these other companies has a founder go and shoot elephants and post about it on their official blog with pictures, after supporting SOPA and demeaning women on national television. Boycotting does nothing, and crying about it even less.