Actually on the side of law enforcement here, accuser has to provide burden of proof. It's pretty hard to prove how stupid and ignorant someone is or is not. Edit: It would make defense by ignorance the default plea and abused horrendously.
Only thing I think law enforcement gets wrong is THEY are allowed to take the defense of being ignorant of the laws they are supposed to be protecting. If anything a cop wrongfully charging someone with an offense and then admitting they didn't know what they were talking about should result in a larger punishment for them, not less.
In my state at least millions in federal funding goes towards projects. Day to day operations are funded by state tax dollars and they still want people to pay ever increasing prices for public transport.
Honytawks argument further falls flat when you consider tax dollars do go to public transport.
Edit:clarified state tax vs federal