But mild looking wild animals (and humans) are anyway too dangerous for those mild and unsuspecting animals (and humans)!
The mild ones need not become wild to get away from such threats. They only need to develop the technique of identifying those mild looking ones with wild features hidden deep in their brains!
Even identifying is not enough; they also should know how to get away from getting caught by those wild teeth and claws!
Remember, evolution is not yet a finished process. It is still continuing and in the intermediate stage.
It is going to take much time before every one is finished as perfectly mild!