I think the biggest idiots are people who let their pets roam free. If you have a cat that goes outside, OF COURSE it's going to get hit by a car! Or eaten by a dog....or mauled by a racoon....whatever, domestic animals do not belong out in the wild on their own.
My dog is an idiot. If I let her run around outside, she would be dead within an hour. She has no traffic intelligence and would run in front of a car without even thinking it could hurt her. That's why she is always on a leash or in a fenced in area.
I understand that accidents happen and pets get loose. It's scary when it happens and you hope you find them before anything goes wrong. But if you let them run free every day, you're tempting fate and it's only a matter of time before something terrible happens.
Of course, I say this as a suburban dweller near a major city. I hear that in rural areas everybody lets their animals run free and it's pretty much accepted. I can't speak to that, but I still think if you don't protect your animals, it's your fault when something bad happens. You can't really blame drivers, you expect to be able to drive around without some animal running in front of you.
The only animals I have ever killed in my car have been birds. I felt a little guilty, but then I realized....wait a second, these things can fly! If they're dumb enough to get killed by a car, they deserve to die. Unless they had broken wings, in which case, they were going to be dead soon from something else anyway. I'd be really broken up if I killed a dog or a cat.