Stupid primtime? There excuse was "too gritty for 9pm" have they ever wached house at 8PM? Drug abuse sounds gritty to me. Have they watched Married with Children back in its day? That's pretty gritty. Have they watched Bones? Skin falling off and nasty looking dead things, thats at 8.
I think its a bad excuse and they just don't want to pay for it. They lost Medium for similar excuses as well. NBC is just a really bad network.