Why whiny people bug me

I figured it out at work the other day. I very strongly want to help patients and customers, and that compassion is what whiny and manipulative people are exploiting. I don't want to be jaded, and I don't want to shy away from letting compassion guide my interaction with people. I don't like it when they take something good about me and use it for their own benefit. Let me save my greatest efforts for people truly in need!