Is this "fair" to native writers? We can debate the ins and outs. But this approach strikes me as pragmatic, ethical, and realistic. If we want to insist that an A is ever and always an A, for all students, then we probably should just massively ramp our admissions criteria and screening for international students, dropping the number admitted to 1 or 2% of the student body perhaps. However, I think there would be enormous costs of doing so, and I don't simply mean the loss of tuition income.