Good leadership involves responsibility to the welfare of the group, which means that some people will get angry at your actions and decisions. It's inevitable, if you're honorable. Trying to get everyone to like you is a sign of mediocrity: you'll avoid the tough decisions, you'll avoid confronting the people who need to be confronted, and you'll avoid offering differential rewards based on differential performance because some people might get upset. Ironically, by procrastinating on the difficult choices, by trying not to get anyone mad, and by treating everyone equally "nicely" regardless of their contributions, you'll simply ensure that the only people you'll wind up angering are the most creative and productive people in the organization.
General Colin Powell, Chairman (Ret.) Joint Chiefs of Staff