I think a lot of people are missing the point that just because a job is a "back office" job, and not a front line job, then it is somehow unnecessary. If the extra 2500 people are all fired, the jobs they were doing still need to get done. But if the 2500 back office people aren't doing them, then guess who will be?
Maybe adding 2500 public service jobs didn't make things "better". But it's also very possible that it stopped them getting worse. I guess we'll find out now.