A terrible decision
The answer to that question is also the answer to the questions:
* Can you checkout the book of laws out of the library?
* Can you buy the book of laws on Amazon? Can you even afford to buy the book of laws?
Your point about purchasing a paper copy of the legal code is spot on. In my state, I asked my local government workers (clerks, law librarians, etc) where to buy a copy of my state's code. There seems to be only one source and it costs more than 700 USD.
For someone who lives on the opposite side of town from the courthouse, or spends more on rent than a potential law book, reading law on paper can be impossible.
There are online versions, but somehow I think that most people wouldn't be willing to suffer through the mountains of legal text on their phones. The interfaces I've seen sometimes even break tab navigation by using javascript references to each item, making them a pain to use on a big screen.
People challenge infractions in court all the time. Theyre not in much danger. There is a process for this that involves courts and sometimes a lawyer.
You're conflating the judicial system with street interactions with the police, where contesting the NYPD is indeed a risky proposition.
In New York City, most infractions are not challengeable in court. Unless you consider the city Finance Department a court or consider its commissioner a judge.
New York has only one, unified judiciary. The mayor and his commissioners are not part of it. The mayor and his commissioners are not judges.
Like any other bureaucracy, if you get a ticket or citation, you're free to contest it. This wasn't a systematic abuse of power -- it was a bureaucratic oversight.
http://www.amlegal.com/codes/client/new-york-city_ny/
In a city where disagreeing with law enforcement's wrong or illegal activity risks violent reaction or death, it is not solely the citizen's obligation to correct law enforcement's mistakes.
Law enforcement tax the citizens to pay professionals to enforce laws. Those professionals have a duty to do their job properly.