There are many people, who do not believe in the idea that one can support violence in fiction and then support it in real life, or other things along those lines. They adhere to a belief system which in this specific aspect does not distinguish between fantasy and reality, and thus assuming they're decent folk, they tend only to root for characters to do decent things. There are also many people, however, who believe that since things that happens in fiction aren't real, there is no imperative to support their own values within fiction necessarily. So, which of these beliefs systems describes you and how you go about plot creation? I personally believe in the latter and thus enjoy having many a rooting interest in psychopaths, but I sometimes write as if I were the former, when I am trying to make a certain statement and do not want the message muddled.