It's that it's taking up a time slot that could be occupied by something better.
Ok, I noticed that several people liked the pilot, for some reason. How can anyone not see how contrived the characters are? The only thing that I liked in the pilot was that the incredibly annoying British woman got killed, so at least she's gone if I decide to give the show another chance. And yes, I know that is not the reaction they had in mind.
They even went out of their way to avoid any possibility of sympathy for the serial killer by making up an extremely lame back story for him. He became a serial killer because his mother preferred to be called "Annie." Seriously? I just sat through an hour and a half of melodrama for that?
It seems like this show is trying to imitate "Criminal Minds," which is a show that I like, mainly because of its realism. Nearly all serial killers become the way they are as a result of a traumatic past, and that's a big part of "Criminal Minds." I don't mind when shows imitate other shows that I like when they do it well, but this one falls utterly short.