I don't think racks, if sized right, are cruel. The main thing I worry about is many times people who have racks, have racks because they have a lot of snakes. What really concerns me about it is whether or not they pay enough attention to the snakes individually. I do feel it's kinda mean to just mess with the snake for a few seconds for feeding and cleaning, and let it spend the rest of its life in a dark tank (although I'm sure many prefur it) Some snakes like interaction and need some stimulus, and if a person has too many snakes, there won't be enough time to take care of the needs of all the snakes, and still have time for some handling.

I'm not saying all people with rack systems do this, but I am sure there are some people out there that do.