"Boycotting does nothing"

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).