Koalas are good for cuddling, not so good for eating although, I suppose, I haven't tried to eat one so I'm only surmising. (I have cuddled one and they're pretty good cuddlers)
To sustain life humans will eat pretty much anything, generally; I think it's in our DNA, the will to survive, and that gives us the ability to do things we may not under normal circumstances.
In exceptional circumstances the instinct will say... you have to eat and no matter what, you have to be in that situation.
I was told koalas are violent... is it true?
Nah, they are not violent. They will get mad with each other at times, protect their young, but I'd not go as far as saying they are violent. They sit up in eucalyptus trees and eat leaves then go to sleep. That's the life of a koala in a nutshell.
I have them over the road in the conservation park and see them regularly. I've tried several times to get a decent photo but they always look like a furry blob high up in a tree so the photos don't come out so well. One day I'll have my zoom lens with me and I'll get a good one. The one in this post was taken at the zoo.