Because traditionally, the risk was either considered acceptable or misunderstood. Co-sleeping causes a lot of unnecessary infant deaths (actually, not reputedl

Because traditionally, the risk was either considered acceptable or misunderstood. Co-sleeping causes a lot of unnecessary infant deaths (actually, not reputedly; look up the advice on this topic in most countries), and a lot of national health agencies strongly recommend that babies have their own crib. Just because it is or was normal in some cultures, doesn't make it safe or a negligible risk. Ignoring evidence-based guidelines for something like this just because it feels better is perhaps not the best way to go about it — I would say 'idiotic'. Sleeping in close proximity can be done in other ways, like the co-sleeping cots that one can put next to the parental bed. It's still not necessary or even good for the baby really, but at least it can be done without unduly increasing the risk of child mortality.