I disagree. A truly evil person intends the consequences of their evil acts. I doubt that Rachel Carson intended to kill millions of people. In contrast, Stalin, Lenin, Hitler, Pol Pot, Mao, Castro, Kim, Cromwell, Robespierre, and many others, intended to kill, and they did with evil in their hearts.
Actually, she had terminal cancer at time of its publication, and fully intended to pay humanity back for her predicament.