I've had rats, mice, rabbits, cats as pets and would have to say that I could never feed a snake a cat. Not that I place them any higher or lower in the spectrum of importance. Cats, for me anyway, have very different and unique personalities. Then again, I've had a few rats with amazing personalities and even a male rabbit.
I dunno, buying frozen/thawed makes it easier. Kind of like buying beef/chicken/pork that's already cut up as opposed to killing the creature youself.
I'm a softy and feel sad for the pinkies that I thaw out to feed my baby snakes but when they've finished eating I always feel happy to have supplied them with a good meal.
That's how it is for me anyhow....