So, vets, humans are animals, if large and sweaty relative to pets. Do you find yourself musing over how they compare in their fragility, their physical quirks, their health problems? Setting aside whatever you get told about treating humans as patients (which would be a pretty interesting question too), what do you think the major points are that would make humans interesting to treat? For example, if you met a vet from the Andromeda galaxy and they pressed you for insights, what would you say?
Not a vet myself, but I’m in human medicine. While there are species differences (such as how acetaminophen is very toxic to cats but humans can take it without problems), many of the same medications and lab tests are used in animals as in humans. In some cases, human MDs do consult on unusual animal cases (and vice versa) because humans and other animals have so much in common…especially if you’re comparing humans to other primates.
As for what would make human medicine interesting to vets, I think in most cases they truly do find animal medicine more interesting. 
It’s worth noting that vet school admissions are typically actually more competitive than human med school admissions (less vet schools), so in general veterinarians have chosen to study animal medicine because they like it better than human medicine.
Short go-to answer: “Humans are yucky and have cooties.” 
Never been interested in humans as patients. Straight to other animals, to me, they are “cooler”.