Nah, see, if you believe that there's no moral absolutes, that would mean that Hitler were a perfectly moral person. Granted that wasn't the common consensus in Nazi Germany, but lets just assume that a society on some south pacific island believes that torture is entirely correct for every outsider. Assuming we believe that people such as Gandi and Mother Theresa were 'moral' people, if we sent people to that island, this tribe of Hitlerites responds by torturing them. Is that right?
If you don't think that there's any moral absolutes, morality really does come down to a pure and simple aesthetic judgement. I like chocolate ice cream more than rocky road. Is that all that morality boils down to? If you say there are no moral absolutes, then you have no ground to make any judgements because as long as somebody or some culture is consistent with their principles that is right.
As per the infanticide response, you can hold a definate moral principle such as killing innocent babies is wrong, but say there's a group of inuit people who have no other choice but to kill the babies for the group of survival, a moral objectivist would say that thats still acceptable.
Here, another example may be human sacrifice. We think that killing humans for that purpose is inexortably wrong. But a different tribe on a different south pacific island may sacrifice people by throwing them into a volcano to appease a god so that they think it prevents an eruption, and thus it turns into a pure and simple utilitarian principle. That believe though, is based on a false belife of factual information. Assumingly, if they knew throwing a human into the volcano would not in fact prevent an eruption, then i'm guessing they wouldn't throw humans into it.
Basically all i'm saying is that if we say that there is no moral absolutes, morality is non existent. There's 3 general terms of morality, No Rules (Ethical Subjectivism), All rules (Ethical Absolutism), and Rules that can be broken (Ethical Objectivism). I'm not as arrogant as i may sound, i'm just not entirely sure of how much people have studied this hence my dumbing things down a bit. This is immensely scattered i admit, hopefully i made some sense, if not, i'll come on in the morning when i've sobered up a bit and clean up my mess.