YY I loved the Deborah Jackson books and also did cosleep from the start. (She doesn't seem to return much on google these days). I had a normal cot and took the side off and strapped it to the bed as the only commercial co-sleeper then was the Arm's Reach one which was £££ as had to be imported from America.
I got a purpose built co-sleeper for DC2 and it was rubbish compared to the home made one, though, again, quite understand why making your own isn't really encouraged - it's a shame because it was so much sturdier, being custom built to the bed, and lasted longer.
I think cosleeping is simply a lot more complicated than cot sleeping. Things can go wrong because an adult bed isn't designed for a baby and you have to actually take steps to make it safer. Some people won't know to do that or will get it wrong especially because there isn't really a good source of info. I know everyone says "Safe sleep seven" these days but I think it's much more complicated than this, and trying to make it sound simple does actually add to the problem.
There was a review recently which again showed that with co-sleeping deaths there is generally an extra risk factor such as adult bedding near the baby, parent having consumed alcohol etc.
Whereas cot guidelines are easy - cots are designed to be safe for babies and you actually have to do stuff to them, like adding bumpers, adding loads of bedding or modifying the angle etc - to make them unsafe.
The problem is when the baby doesn't take easily to it - that's when I think you need a more nuanced approach and ideally one to one guidance from somebody with training and a good understanding of the issues. Which unfortunately isn't really practical especially with staffing issues.