They can't really ignore what happened in major books that came out within the last year.
Actually, they absolutely can. This month, a book came out, a major book that will have probably six times as many readers as Batgirl if not more, in which Babs said, strong, resolved and happy, "I love my life, every day." Johns was just like, "Hey, Babs isn't emo, Dixon and Simone just spent a decade evolving her out of that. So that's what I'm going to write." He totally, completely, and cheerfully ignored or dismissed the bullshit of the ORACLE mini and the crap ending of BoP, and wrote the character properly.
Just like the writers and editors responsible for said mini totally, completely and cheerfully ignored or dismissed everything that Dixon and Simone had done.
Not giving a shit about continuity or recent character behavior is sort of a mainstay of modern comics writing. Yet for some reason, it only ever seems to apply when somebody wants to write a character badly. When it comes time to gloss over all the crap and just write the good stuff, suddenly it's all "oh no, we gotta respect continuity, we gotta work with the story as it stands now." I call bullshit. If Beechen isn't required to respect anything Puckett or Gabyrich did, Miller isn't required to respect anything Beechen or Vanhook did.