The average citizen does not know to consider the subsequent order effects of a decision. It is for the politicians to do this job, but they are failing.
An insightful example of such iatrogenic results is the ban the box measures. “Banning the box” was a good faith attempt to get people with largely unimportant criminal histories back into the workforce by removing the ability to ask somebody if they have a record. It made the issue worse - the outcome was that employers hired fewer minorities because, without the ability to ascertain the criminal behaviour of a prospective employee, people would guess. Any individual in any group which is more highly involved in crime on average is unfairly penalised.

Good intentions are not enough.