Laws and their enforcement will always have some nonzero amount of selectivity by the localized nature of the universe but good legislation confronts these challenges proactively and tries to make prosecutorial discretion closer to the question: What should the Punishment be? Rather than: Is this behavior Punishable?

>> an implicit status quo that could be changed any time

> So is a history of enforcement!

Are you really saying that history can be changed at any time?

While there will always be jurisprudence that attempts to advance precedent, a history of consistent enforcement cannot, in fact, be changed. People will always have vulnerability to novel interpretations and surprising re-interpretations of the law, but laws which sit on the books IGNORED can easily lead to essentially undefined behavior which I have no doubt you can understand the potential pernicious nature of...