Love often masquerades as hate is a more correct argument. Actual hate IS the opposite of a love, the sticky part is that when someone is burned by one that they love or the feelings turn out not to be mutual, the one in love will fool themselves into believing they hate the person instead of dealing with the fact that they do love the person. That is what leads to the kooky antics of spurned lovers.
If you truely hated a person you would do everything in your power to harm them within the confines of the law, or at least what you thought you could get away with. Apathy is more effective in injuring someone who has spurned you though, that I would agree. People don't typically make clean breaks so both parties probably harbor feelings for the other one so apathy would be more damaging, but that doesn't make it opposite of love.
If you truely hated a person you would do everything in your power to harm them within the confines of the law, or at least what you thought you could get away with. Apathy is more effective in injuring someone who has spurned you though, that I would agree. People don't typically make clean breaks so both parties probably harbor feelings for the other one so apathy would be more damaging, but that doesn't make it opposite of love.
