Many slang words have entered the English language in Generation Y. That goes without saying, all generations have had their own slang and words can change drastically from generation to generation, but few words entered the language that strike such an egotistical cord as "hater".
"Hater" is often used, as many are aware of, to describe someone that doesn't like the way a certain person acts. The biggest reason why is that it allows the person using the word to dismiss any criticism as just being someone extremely jealous of their abilities and that they don't have any real faults. This mindset is possibly the Achilles heel of Generation Y's work ethic.
When a society can't learn to change its mistakes it is doomed to fail. When people throw around a word like "hater" to dismiss all critics, no matter how valid the criticism is, it leaves no room for improvement. It also misleads future generations to believe that people will only say things about your attitude because they wish they were you and won't bother trying to change themselves.
"Hater" may only be a word, but it's a pretty disastrous word. Generation Y already has a reputation for being needlessly cocky and self centered. This type of attitude doesn't help things. Hopefully in the near future people will realize how ignorant the word is and will quit using it to promote their own self delusions.