Final answer:
John D. Rockefeller and Andrew Carnegie were called \"robber barons\" due to their predatory and often unethical business practices, such as horizontal integration and monopolistic activities that prioritized profit over social welfare.
Step-by-step explanation:
Business tycoons like John D. Rockefeller and Andrew Carnegie were referred to as \"robber barons\" for specific reasons. Rockefeller, in particular, engaged in predatory business practices, such as forcing smaller competitors out of business and creating monopolies through horizontal integration. These actions often resulted in gaining unfair market advantage, disregarding the well-being of workers and smaller businesses.
For instance, Standard Oil, owned by Rockefeller, was notorious for its aggressive strategies that many critics considered exploitative. In contrast to the philanthropic image that some tycoons, like Carnegie, tried to cultivate, their approach to labor and competition could be harsh, with little concern for social consequences.