I agree Torino and I want to say this as well:
Controlled crying is always an emotive and polarising topic on here and probably elsewhere when it is discussed, precisely for the reason that you say. Plenty of people have done it and the last thing they want to hear is that it could have damaged their child, particularly when as you say various health care professionals and resources still advocate it or don't dissuade from it.
For me, though, it's a bit like breastfeeding (and probably plenty of other issues that others can name). We are all aware of the breast is best advice and the mountain of research that sits behind it. I tried breastfeeding and it didn't work for us. I would be the first to admit that it wasn't that I *couldn't*. J latched (badly) and was getting milk, he survived exclusively on it for 2 weeks, but I found it very painful and stressful and found it difficult to cope. It was affecting me psychologically. We made the decision to go to mixed feeding, knowing it wasn't the gold standard, but taking all the factors into account it was the best thing overall we could do for all of us.
I've come to terms with that and it doesn't particularly worry me, but I have a friend who attempted to breastfeed, had insurmountable problems (not like mine, she really couldn't even with plenty of professional help) and she still feels guilty. So she finds all the facebook posts and breast is best info distressing, because it triggers that for her.
From the small amount of evidence I've seen, the jury is still out on CC. But there is lots of evidence that sleep deprivation affects people psychologically and physically. So I can understand that for some families it's not just a matter of persevering with the more gentle methods, they need to consider the whole family's needs and do what's best for the group as a whole.
I've had it said to me many times since I stopped breastfeeding and I honestly believe it's true: A happy mummy makes for a happy baby.
Well done to the mummies and babies that are having success and getting some sleep xxx