I believe Jimmy Kimmel said it best about Palmer being a douchebag who wanted the head of a lion in his man cave so all his buddies could sit around drinking scotch and telling him how awesome he is.
It is apparent that Walter Palmer is a sociopath with an inferiority complex. He has a grandiose self-image and lack of empathy. He needs validation, thus why he is a “trophy hunter”. A trophy’s purpose is to serve as recognition or merit for an achievement. He had a successful practice that produced enough profit to afford his lavish big game hunts. He feels inferior in life, perhaps his wife is the Alpha in the marriage? Regardless, his inferiority triggers something within to insert himself in a position of power over animals, animals that aren’t fighting back. It is like when a bully picks on the weakest kid.
Through his hunts he has convinced himself that he is a Great White Hunter; fearless and boasting about his exceptional archery skills. Yet, now that he is being hunted, he has gone into hiding. Cowards hide. If he is really innocent, why is he hiding? Why isn’t he publicly on a mission to help prosecute the “local and professional guides” whose expertise he relied upon?