Whether you or I would morally approve of it, it is likely that the number of cops, politicians and tax collectors would drop rather dramatically that day.
This actually made me laugh! But I do agree with you! Things would be a lot different if people in power, with badges or protected by people with badges, knew those they're trying to screw are now free to come after them.
Also, if making murder legal might raise some eyebrows, even a beat-the-shit-out-of-anyone-with-no-consquences law would be useful!