From what little we know, the accused in this case was working as a taxi driver. A female passenger complained that he had raped her. He said that not only did he not rape her, he had had no physical contact whatever with her.
So, assuming that he spoke the truth, there would be no forensic evidence to the contrary.
And yet, the police believed the woman. Why?
Guessing again, it's reasonable to assume that they had some evidence (we know that there must have been enough, in the opinion of the CPS, otherwise the man would not have been charged). It's also possible that this was not the first complaint against this man, again we don't know, but the police must have had some reason to believe that he was, or may be guilty, and as people typically behave in the future as they have behaved in the past, it's fairly likely that the police had some reason to believe that he was a likely candidate for rape.
The CPS then examined all of the evidence that the police had, they came to the same conclusion as the police and, more crucially, believed (wrongly as it happened) that he would be convicted.
None of these beliefs make the person guilty, but their existence does demonstrate that there was at least some evidence of his guilt, because without this evidence he would not have been charged.
Therefore, I don't believe that it is unfair or disproportionate to refer to his aquittal on his DBS record. If he is entirely innocent, then he may not be able to work unsupervised with children, which would be unfair to him, if he is guilty then that reference may stop a child from being raped. Is it really more important to make sure that he can do exactly the job that he would like to do, or is it more important to protect children from rapists?