John didn't had many friends, in fact, he didn't had any friends, less a girlfriend, not that he was ugly, just that he LOVED loneliness, he enjoyed it.

What happens when he arrives at ponyville? He needs a job, he needs a school and most importantly, he needs friends. Will he be able to change, and discover a new and spectacular world. Or, will he return to the path of loneliness and isolation.

(Based on a friend's patient, he is a psychologist. His history left me very perturbed)

And yes, the ponies are humanized, but, They still have the horns and wings, and they can use them.