Do mass murderers such as the "Batman Shooter" & recent shooter do it because they hate people?

[Victoria]

I think if we knew exactly why these people did these things, we would be able to prevent them more easily. I also think this is a much more valid question than a lot that have been flying around the internet.
We need to know why.
I think a combination of things, social alienation, poor future prospects, existentialism, not being used to hearing "no" or learning to deal with failure (both real and imagined) all swirl together in the pressure pot until one day it all goes bang. When you add easy access to a firearm into that mix it gets very ugly.
What we need to do is get good quality mental health care in place and erase the social stigma attached to admitting you can't cope (1 in 3 people have a mental illness at some point after all) . Then we need to seriously restrict access to firearms (the UK is doing OK in that regard and mainly needs to focus on illegal firearms. These are usually held by criminal gangs, not families of mentally ill teens that snap, so are a slightly different category of crime) but most importantly we need to understand why some people can cope and others can't.

I also think certain people may do it to gain some sort of sick notriety, or fame. I hate that we make these killers famous, so that everyone knows their names while the victims names go forgotten.