Dunno really.
I'm not convinced that CRB is at fault for providing the info that's there (and under legislation dating from the 70s, some jobs are allowed to ask about spent convictions) - apart from people who have been placed on (whatever it's called these days) the list of people who are specifically barred from working with children and / or vulnerable adults, it is not the CRB's role to say "yes you may employ this person" / "no you may not employ this person" - all they do is provide information.
what's at fault is the way crap employers use / have used the info provided.
As far as a job working with children is concerned, a caution for shop-lifting 20 years ago is really neither here nor there and any sensible employer should regard it as such. If an employer is rejecting someone for a job working with children on that basis alone, they are doing it wrong. (certainly breaching guidelines if not the actual terms of the ROA Act)
Spent fraud convictions might however be relevant for someone applying to become an accountant.
I would also argue that employers should be allowed to use some discretion with "sex offences" - someone who, 30 years ago and when they were 16 and a bit, got done for having a consensual relationship with someone who was then 15 and a bit, is hardly a threat to children.
Until fairly recently, (potential) employers were allowed to use a degree of common sense about that sort of thing. Then there was a tabloid "OMG - there are SEX OFFENDERS working in schools" panic and the government panicked.