Wait so, CASE 2 MILD SPOILERSPhoenix Wright is disbarred for presenting a piece of forged evidence which no one can prove he knew was forged or had wanted forged, in the most obvious of set ups in the entire world, but Simon Blackquill murders a man and is still a Prosecutor? Lololol. I guess they just figured that since so many Prosecutors have been accused of murder it wasn't grounds for losing your job. Like seriously, Edgeworth, Von Karma, Lana Skye, Godot, Jacques Portsman. So many Prosecutors accused of murder. Oh, and Franziska von Karma, though that was very, very short-lived.
This particular bias was already covered in Case 1-5 which
retcons Edgeworth's backstory into revealing that he has presented illegal evidence in the past, when that was the only case to establish connections with AA4 - a game where Wright gets disbarred for doing the exact same thing that Edgeworth did under the similar circumstances. Wright got his career crushed while Edgeworth got another "you got lucky this time" and just a bunch of negative murmurs. Blackquill being chosen as prosecutor at the Chief Prosecutor's request also highlights another thing 1-5 delved into, which is their influence in cases.