I actually liked those Harry Potter fics. It seems to fit, at least to me, that the Wizarding World has a lot of laws about what kinds of magic can be used, and where, but not much about interpersonal relations. Like, you can be charged for breaking another person's wards, or defeating their anti-theft protections, or ensorcelling another person's property, but not for breaking/entering or theft. Sirius wasn't sent to Azkaban because he killed 13 muggles and Peter Pettigrew, but because he used magic in a muggle area and used offensive spells upon another wizard without a license or whatever. This also nicely dovetails into why Rita Skeeter could get away with what she did: there are no rules about what can be printed, such as Slander or Libel laws, only laws about how various potential spying spells can be used, and registration for the Animagus forms, so as long as she isn't caught out as an Animagus she can't be charged.
Back before the Statute of Secrecy, the non-magicals dealt with the crimes not directly about the magic used, and the Wizarding world just...never made those laws.