We viewed them as a cost of doing business. Some small accounts got nuked. :shrug: If we had to have humans investigate everything, and produce reports / interpretations that nuked customers found satisfactory, we wouldn't have been willing to service accounts under probably $40k/year.
And keep in mind the ecosystem is filthy with fraud, particularly on the low end. There very much are groups of organized thieves actively exploiting adtech.
And as @PeterisP says... look, we're not a court. We're a private business that is refusing to do further business with someone. Our right to do this was very clearly explained before the beginning of any relationship, and agreed to by that someone. If that someone doesn't like it, their recourse is to not do business with us.