"I cannot think of any reason not to use "people-hating" instead other than for dramatic effect" Same reason you wouldn't shorten "Bob and Santa Claus" to "two

"I cannot think of any reason not to use "people-hating" instead other than for dramatic effect" Same reason you wouldn't shorten "Bob and Santa Claus" to "two people": the second subject is a childish fantasy utterly unrelated to reality...