Co-sleeping is one of those topics quite hard for women who haven't had children to understand not meaning to sound condescending but I know it does, I remember thinking "OMG why the hell would I ever do that, it's so unsafe, what if I roll on baby, the baby will just sleep in a Moses basket" so naive, I actually did it for a short while with both my 2. Not all babies just sleep where you want them to sleep. Babies are programmed to WANT to be next to mum, google the fourth trimester. Co sleeping can be very safe, there's a safe way of doing it and those who do it properly reduce their chances of SIDS, it's a very misunderstood topic.
As a breastfeeding mother co sleeping was very natural, I actually personally didn't like doing it as I like my own space, but it was where my son felt safest and slept best when he was very young, I had a co sleeping cot so he was inches away from me but if he wouldn't settle all I had to do was put him next to me and he would fall asleep instantly, being next to their mum is their safe place, they can smell her, feel her, hear her. There are safe positions to sleep and not suffocate baby and BF mums are very intune with their babies, I am normally a very fidgety sleeper but when my son was next to me I wouldn't move a muscle- I would wake up with cramp! You sleep very differently when BF it's all down to the hormones. I personally wouldn't feel safe sleeping with a very young baby if I was FF but that's my own opinion.
They have to keep advice very generic to simplify it, it's better to tell everyone not to do it than get complicated explaining how to do it safely and risk sending mixed messages to those who are higher risk, my MW actually suggested me to do it as she knew my situation. That said it may not be safe if you're formula feeding, it isn't safe if you've drank, taken drugs, or smoke, I didn't do it with DH in bed as he wouldn't have been in tune. I would say it's something to keep an open mind about, it was something I didnt want to do either time but had to, it's very important if you do do it to research it.
Of course lots of mums haven't felt the need to co sleep and may feel just as strongly about it as they did before, but it is a topic I very frequently see people changing their mind about.
Definitely research fourth trimester.