When I made the reference, I was more considering post-apocalyptic science fiction like Soylent Green—people killed in mass numbers to serve as food (which would literally be the case here, since Malack feeds on humans). If I was referencing any aspect of real life at all, it was factory farming, where humans have special chambers built to slaughter millions of cows and pigs each year all in the name of efficiency. I'm a vegetarian.
I will not pretend that it never occurred to me that anyone could take it any other way, but it was not my intent. Ultimately, I felt that the differences between the reference and the historical event were enough that it would not be necessarily seen that way—the inclusion of a religious/sacrificial angle and the fact that Malack literally will eat the people killed seemed, at the time, to push it well into the realm of a fantasy event.
I'm not going to bother responding to the other charges about how I trivialized the Holocaust, because I don't feel that I did. I wrote a line with one specific thing in mind, and I did not properly gauge how other people would take that line. That's a mistake on my part, not an intentional transgression.