Never Read the Comments
medium.com
medium.com
Jokes aside, it's easy to say 'trolls will be trolls' and move on and some will even say that it's not even worth writing about hateful comments on the internet anymore, however, sharing experiences like these do help to empathize with others and act as reminders to everyone about their own biases when making comments (sexist, racist, or what not).
As for trolls and haters, I think there are many (both simple and complex) reasons why people try to lash out at others even if they're not of that personality in their offline lives. It's naive to think there's a single reason.
The episode of TAL does a good job of describing just one of these encounters: http://www.thisamericanlife.org/radio-archives/episode/545/i...
Sorry, but this is useless fluff.