This post has been manually curated by the Decentralised Sustainable EcoSystem movement by various stake holders and charitable donors to support Entrepreneurs favouring a stable STEEM ecosystem

 

This question can have a very complex answer despite the question seemed simple; but a simple question can easily lead to simple answer:

Too much Self Focused but Not Knowing the true Self

Just like @voice.direct has detailed it out, the self-dissatisfaction leads to much undesirable output.
The first question before the hate; is that, do you know who you truly are and your worth from the day you are born?
Without that, humans tend to have an "identity crisis" that leads to self-question, dissatisfaction, insecure, compare, compete, and it goes on and on negatively and result to => HATE.