As an ex teacher, I'm shocked to see some of the blasé attitudes to keeping children safe and the training for that.
I had to sit through hours of it. Yes, it was boring. Yes, I'd heard it the previous year, and the year before that, and the year before that. But I still thought it was the most important part of my job to listen to it and attend it. Because god forbid something happens... and it did happen at my previous school. The first thing people ask is 'Were the teachers involved trained? Did they follow the correct procedure? Was anyone else aware of safeguarding issues but did not report it?'
It's not just 'if you see something odd, make sure you mention it to someone'. It's 'This is OUR procedure. These are our SAFEGUARDING OFFICERS. If you see or hear anything, report it to the safeguarding officer, fill out a form, if necessary interview the child and write things down in their words'.
DBS checks are by no means perfect. They do not catch everyone who has a criminal history. But they go some way to protecting children from dangerous individuals and as a parent, I would damn well want it in place rather than not. It's not just paedophiles. Think violent criminal history too?
OP, as someone who has filled out multiple DBS forms, even if your DH has a DBS with his current job, he still needs a new one for that new organisation. I know it's time consuming and a pain in the arse but it's necessary. I can see how it might put someone off, but if that's the case then I'd say their desire to help children and be involved isn't that strong anyway. It's a standard procedure for every single school and youth organisation. Even though I'd been a teacher for 3 years, I still had to fill out a DBS for being an instructor in the Army Cadets.