Tracy needed somewhere to stay, how was he supposed to know that it was in another universe? Now he'll somehow have to hold down a job on Earth while living as a pony in Equestria. It's either that, or say goodbye to being human.
Stories about ponies are stories about people. Every challenge is an opportunity to change. My Patrons let me keep writing, at: https://www.patreon.com/RealStarscribe