I intentionally hit citrus fruit on the road for fun to see how good my aim is, but I would NEVER think about hitting a living animal. I feel bad enough when squirrels run in front of my car (I can count on one hand how many times I actually hit one, many more escape, but those few unlucky ones make me feel awful!), I am disgusted anyone would do it intentionally. Unfortunately my coworkers have seen people intentionally swerve to hit animals, especially snake. Around here we don't even really have turtles that could cross the roads (out in the deserts there are tortoises though, and lots of areas where they live actually have fences and underpasses to keep tortoises off the roads), but plenty of snakes, mammals, and birds get hit.
BUT I've also seen people move animals off the road, so there are good people out there. If possible, I stop to move roadkill off the roads too, so other animals don't get hit trying to eat it.