They do seem really morbid and sadistic to me...but I grew up with Cinderella, Mother Goose, and the like. As a kid, if I had read the thumb sucking or playing with matches story, I sure as hell wouldn't have sucked my thumb or played with matches, that's for sure!
Just as a side note...the reason I asked all this is because I am going to a fairy tale themed party next month...and the tailor who cuts off thumbs was my immediate choice for my costume...I just had to find the fairytale. It's interesting you should mention the Irish ones, snowy, because after hubby read this one, he decided he wanted to research some Irish ones and choose one for his costume