I'm not sure I can say "hate" so much as my pet peeves when it comes to personality traits. More recently I ran into another case of hyped infatuation instead of understanding what it means to really love someone. It's too common for people to fall in love with the idea of love, move too quickly because of those emotions, and hurt both themselves and the person they think they're in love with. What's worse is when you see a person do that with two people at the same time, then throw a temper tantrum when both people don't behave the way said person wants them to.
Love isn't a role playing game, where if one presses the right buttons, one gets a programmed result. Instant gratification doesn't happen when humans who seek deep, meaningful relationships are involved. It takes time to build a solid foundation upon which love, and trust can grow. The sad truth is that it's very easy to get caught up in someone else's emotions.
If there's one personality type I can say I hate dealing with, it's the kind that throws him/herself into emotions and only act on impulse. When this type feels warm fuzzies that could lead to love, they run away blindly. When they hate, they have tunnel vision, and place full blame on the other person without looking at all sides of the situation.
The moral of the last of this: There's two sides to every story. If you see someone vent-vomit all over their Facebook, there's a good chance that the person they act as if they hate so much has a story, and are being unfairly put on trial. Try not to jump on the hate bandwagon. If they ask for advice, ask about the other person, and try to find out what really happened. There's a chance that even your best friend is being a douche as well. As much as we want to believe in our friends, no one's perfect. And in a fight, no one's the winner.