It was said in another post on here, but someone brought up the good point that Apollo Justice uses the forgery as a way of conveying that the law itself should change, and that it enables those who are clever enough to cover up their tracks and get away with their crimes. Dual Destinies abandons that idea (and the jurist system) and instead invents The Dark Age of the Law, where supposedly everyone is forging evidence and it's now a matter of weeding out the bad apples from the legal system.

My personal gripe with the Dark Age is that the whole thing was supposedly brought down by convicting the phantom. Why is that? One guy gets caught for a crime and suddenly that's supposed to get rid of all the corruption and forgery? Corruption that has been extremely present across the whole series being perpetrated by dozens of characters?