People who want to be like you but can't, might hate you. While a psychologically stable person will try to become better, an unstable person will just hate anyone who is better than him.
So many people hate others to elevate their own self-esteem and feel better about themselves. People could be hating you because they have self-esteem issues and not because you are bad or defective (See why we strive to feel superior).
When people see your success and remember that they don't have any, they might hate you for it. Brave people will try to be successful as well, while others will hate you.
People hate others when they harm them either directly or indirectly. By getting the attention people were looking for, you would be harming some of them indirectly, and as a result that group might hate you (see Why are some people attention seekers).
People can hate others when they believe they are living great lives. This usually happens when people compare themselves to others and find out that they are unfortunate compared to them.
People who aren't helpless improve their lives, change and seek new goals. The ones who are helpless just hate the ones who are bright, simply because they can't do anything to become like them.
When a person thinks that someone is a threat, he might hate him. People could be hating you because they feel insecure.
Jealousy is one of the most common reasons behind hatred. A person who is jealous of you might hate you if the emotions go out of his control (See why we become jealous).
If you are very smart, for example, and one of your friends believes he isn't, the moment he sees you, he might remember this fact and as a result he might hate you for it.
People can unconsciously recall other people who resemble you when they first meet you. If you unconsciously remind a person of someone who hurt him, he might hate you. The problem here is with the person's past not you.
That's one kind of jealousy. When a person finds that you have many things that he doesn't have, he might assume that you don't deserve those things in order to make himself feel better and as a result he might hate you.
Hatred is an emotion that has the purpose of keeping people away from the ones they hate. If people feel inferior to you then their minds might let them hate you in order to stay away from you.
When a person fails to explain why someone is better than him he might start to look for any flaws to put that person down in order to increase his self-esteem. A person can hate you because that's the only way for him to remain psychologically stable.
A person might hate you because you took something that he always wanted to have. That thing can be a job, a promotion or even the heart of someone. Helplessness and envy are the main reasons for hatred in such a case.
A person can hate you to deny one of their flaws. By claiming that you have a certain flaw then avoiding you, that person would successfully deny the problem he already has. It's not uncommon for a person who has a certain flaw to hate others for it (See why people lie to themselves).