"You are complaining about an unethical company and solving the problem by doing an illegal action. Isn't this selfish?"

No, it is called "civil disobedience" and it is one of the few effective nonviolent ways to promote change. Further, the law is completely out of alignment is this regard; it is in no way promoting the progress of science or useful arts, nor is it helping to ensure that a needed industry remain solvent. We do not need the textbook publishing industry, because we have a much faster, cheaper, and effective way to distribute textbooks: the Internet. If the law continues to protect these unethical and laughably anachronistic businesses, then the law itself is wrong.

Civil disobedience is a public protest and has been about being willing to go to jail in protest of unjust laws. It is critical that the authorities are aware that you break the laws and you are available to be arrested. People then become outraged at the injustice of your imprisonment, or so you hope.

Sitting at home downloading stuff and then posting about it using an anonymous handle is not civil disobedience.

Slavery at one point was unethical yet legal. Do you consider the people who ran the underground railroad selfish?