The fact is that there are enough laws (traffic and other) on the books to write citations for peopole every day for any number of violations. It is impossible in a practical sense to know and follow every law on the books, and your posts are insinuating that every time someone breaks the smallest of laws, they should willingly accept the legal consequences without a complaint. However, you are failing to realize that we do not live in some computer program with black and white rules for everything. The laws are made for people (and by people) and are inherently flawed in that strict rules written in some book cannot adequately govern all of the situations that citizens get into every day. Let's also not forget that at some point slavery was legal, women could not vote, cars had no speed limit, etc, etc, etc. These were all changed because they were WRONG, unethical, and unfair. And before these laws were changed, the people in the US had to get pissed, violate the laws, complain about it, stir up public opinion, and finally get the laws changed. And they weren't wrong for doing so. Actually quite the contrary.
People feel that the red light cameras are unjust because they are more expensive and time consuming to fight than the violation deserves. Not to mention the state does not have to expend much effort at all to issue these tickets & therefore has very little to lose and much to gain by approving these. It is a conflict of interest as they receive money for essentially doing nothing. If a police officer takes the time to pull you over and write you a ticket there is some expectation (and I think a fair one) that the police officer is enforcing laws that are being violated to the degree that they are affecting public safety. Whatever your opinion on this is, most people feel that this is unjust, and frankly this is a major determining factor in which laws are adopted, as they are to a large degree otherwise arbitrary. I'm sure others could expound much more on this as to why being issued a ticket by a camera company is somehow 'not right' versus being given one by a police officer.
But in answer to your statement that "if you broke the law, you should just pony up the cash": if you think that all laws should just be followed without question, and that if it is on the books it is by nature a just law, you are an idiot.