Most likely the author has Aki as her self insert. It's the only way to explain how she got away with being as unlikable as she was in the early chapters. She realizes that oh, surprise not even masochists enjoy having their feelings trampled into the ground, so author tries to show Aki on a more innocent light, and put a flashback of her as a kid. Except she was as annoying and bratty even back then, so the author tries to blame her awful behavior on Yoshino despite her calling him piggy was perfectly in character for the Aki of back then. Author gets more annoyed at some people daring to like maid or Neko over her self insert so she boycotts them both instead of trying to make Aki less of a ... y'know.
But alas, the manga is ending and fans are saying that the end was predictable and the series cliched, so she plans the last bait and switch. To add insult to injury, she uses Yoshino and Neko again to pull out a 180° personality change out of freaking nowhere in the last minute instead of developing her.
Was Aki developed as a character? No. Did she ever understand that maybe, just maybe she should have felt bad about the people she trampled over the last years? No. Did she have to fight for her love? No. Everything from the beginning was given to her on a silver platter and that never changed even once when this trainwreck of a manga ended. This is Infinite Stratos all over again, just that this time Tiv served well in distracting us from the awful writing. No wonder everyone is angry.