Throughout history, human civilization has been cursed by tyranny. Time and again, power is concentrated in institutions that rule by coercion and force. Humans have suffered through totalitarianism, dictatorships, and fascism repeatedly. Untold suffering and death have occurred.
But such times have always been marked by resistance. Courageous individuals and movements have fought back with a variety of tactics from open revolt to furtive sabotage. The rate of success in overthrowing particular tyrannical institutions has been mixed (though none of them ever last forever anyway of course) but that is not the only way to weigh the value of freedom fighters. Is it not worthy, in and of itself, to strive on behalf of life?