They (many of the misinformed reviewers/commenters on sites) say these kind of games may not serve much a purpose; and could in fact, be nothing more than mayhem made for psychopaths that live for death and dismenberment (IE- "Slasher Film Fans"). And yes, there are plenty of them. Hell, what site doesn't have a commenter that mentions something along this line about any game with violence in it? It's mentioned almost non-stop. There's even a verbal pattern to them that can be identified at a glance. I don't even need to read them to know it's context. The walls of text usually are enough of a giveaway.
Here's at least a hypothetical situation I can answer with.
HYPOTHETICAL:
What if you're an agent of some sort (like FBI, SWAT, or something (least you'd expect to enjoy such games)) playing this kind of game in your time off; not for investigation purposes (to further a political agenda), but because it looked interesting, you're a fan of roguelikes, and are not a zealous pacifist (that vomits at the first sign of virtual blood; you know, conservatives that the media pays attention to)? You enjoy the game as much as you can learn random crap via simulation experience (like Gran Turismo, and learning a bit about cars by tweaking them in-game, and feeling the difference by even a minute alteration (best example I could come up with at the time)); and you also go through a series of thought processes and put yourself in the killer's mind. What better way to think like a killer, than to be one yourself (in a simulated world)? Okay, how did he do it and what are his intentions (IE- the many features to be implemented/further suggested)? (and so on)
Well, the additional recreational experience gained from playing a game like this could at least spark some imagination and further clue-seeking to the player/agent in his line of work, purely by wandering thought. I mean, I've realized some interesting things, or come up with some interesting concepts completely out of the blue due to a wandering/lingering though (not entirely related to topic); and some of them could actually be applied; though not all are practical, or in some cases legal.
I mean, my argument is simply (and classically), don't judge a frikkin' book (oh, sorry, "e-book") by it's cover (crap, I meant header/title).
FAKEEDIT:
That last part is for the kind of shmucks we all know are annoying as hell about stuff like that. I mean, paper, what's that? (IE- also the type of people that make those silly assumptions.)