I know we're not meant to do threads about threads but it's a recurring theme. Every time it crops up, people get nasty with each other.
Now, I have considered CC and decided not to do it for my own reasons. I think it's great that people post information and their opinion on whether its good/bad/helpful/unhelpful. And that can help people make their decisions about it, and also to adjust their expectations (which has helped me a lot).
But a lot of the time, people posting on the sleep threads are desperate. If they have tried other things and just can't cope, it's harsh to attack them and make them feel guilty. Sleep deprivation sends you crazy. I would rather a parent did CC than ended up harming themselves or their baby because they are just SO TIRED.