Why would someone become a serial outside tree and plant assaulter and is there help?

Because they don't like trees and plants. Especially if these trees and plants are in your yard and they don't like the look of them. I'd say a water hose on full blast sprayed in their direction would be a lot of help.

I like things growing on my property. However, since we have this Emerald Ash Borer insect killing all the ash trees, I gotta whip out the chain saw and cut them down.  

As opposed to what, an inside tree and plant assaulter? As for help, two or three people can assault more trees and plants than one person can.

     They need a tree shrink.
Saw this guy walking down the ST
and cursing out every tree he saw
and assaulting each and everyone
of them saying the whole world
needs to get rid of all the trees.
   I said leave the trees alone.
He said F...ing tree lover 
and tried to assault me...LOL

I never meant to kill that cactus my ex gave me as a gift. Yes, if you NEVER water a cactus, it will die :(

not sure