What this legislation is is a legislated plea bargain. The penalty for prior breaking of US law is a $5,000 fine. In terms of the US criminal justice system that is a pretty hefty fine for a first offense. [I am not sure if the offense is a felony or not.]
Now you might respond that the person copping the plea will not have a criminal record. Since the US has tons of diversion programs where first offenders who commit serious misdemeanors end up without a criminal record, I don’t see such a big difference.
Should people who get caught embezzling be allowed to buy for $5,000 plenary indulgences which would permit them to continue embezzling with no further penalty?
What the government's peddling isn't actually amnesty, but if anything indulgences are far worse.