One big issue is that most people don’t have pet insurance. But they do have medical insurance. As a consequence they are completely surprised by the out-of-pocket costs of medical procedures.
Hip surgery (to pick something at random) is hip surgery, even if it’s for a dog. It still costs thousands of dollars. But a significant portion of the population expects to pay what they would pay for insurance-covered human surgery, eg a couple hundred dollars at most. And when they see the bill they accuse the vet of “only being in it for the money” if they won’t significantly discount the price.
Meanwhile, the vet is paying back $150,000 in student loans, same as a human doctor, but only making a third of the pay.