People who don't understand that animals feel pain.
example from this week - cat brought to vet for shots only, ask the owner if anything was different at home, "nope, he's been fine, eating and drinking normally". Pull out the cat and its leg is all sorts of wrong..."oh yeah, he's been limping for a week, but he's still eating and not crying out, so I guess he's not in pain" says the owner ... "Sir, this leg is broken!" and they were surprised![]()
on a lighter note, people who take absolutely forever to order food at a kiosk like it is a life-altering decision