Ask yourself this; after having been a victim of a crime, would you report it to the police if you knew that as part of the police investigation they would investigate every part of your life for possible criminal activity.
Perhaps those believing that they had nothing to hide might answer yes, but are you sure that all the tyre tread depths on your car are OK, and you have remembered to renew your photo driving licence, you have paid the correct tax on any income etc.
I would not expect the police to investigate my immigration status when I report a crime (although I was born and have lived in the UK all my life) – why should the police investigate someone else’s immigration status just because of the colour of their skin or their name?
I believe that this super-complaint should succeed, the police should stop asking for the place of birth of people they interview - their name & address should be sufficient to identify them.