Plenty of innocent people have. And many states permanently strip voting rights if you are convicted of (plead guilty to) a felony. So the folks most likely to have been adversely affected by this cannot take part in elections to fix the problem.

Check out public defender Twitter. It's a real eye-opener. Police officers still on the force but put on DA lists to never call because they've lied so often on the stand that even the judges know automatically they're full of it. (Almost never charged with perjury though.) Judges constantly handing out bail for minor offenses they know the defendant can't hope to pay even though they aren't a flight risk. DAs regularly withholding exculpatory evidence until just before a trial date in the hopes the (innocent) person agrees to a plea deal while they rot in holding for months.

Threatening to fake DNA evidence is just the tip of the iceberg.