I assume they're saying that, in an absolute sense, all systems of law are arbitrary and capricious. Some might be much better than others, but none are sufficiently fair or transparent to be "good".
The extent to which you agree with that is a question of political philosophy :).
I can't say I'm well versed in this idea but if people are creating the laws they've got some motivations and trigger for the law.... I think we can evaluate those on some sort of practicality / sense of justice or other scale rather than declare them all arbitrary.
The extent to which you agree with that is a question of political philosophy :).