I don't know, I have the feeling that they ran out of source material given the way the 'Arise' series/movie went; basically a lot of action and little content that made GitS great, e.g. in the first movie, the business of symex (sp?) erasures not being technically possible yet, so the idea of some moneyless peon who's been hacked and will continue to suffer false memory flashbacks, showing that great things are possible in the future, but they definitely have their drawbacks and those without the means to throw money at technical problems are even more at risk from this great future, so they're at a greater disadvantage than before that tech era. The 'Arise' movie had one interesting bit in about the cyberization (sp?) industry pushing to classify those who don't want it as mentally ill.
Otherwise there was an awful lot of bollocks in the 'Arise' series, e.g. "stuxnet" left, right and centre, which made no technical sense. In the 'SAC' series it wasn't as bad but it got a bit grating at times when cyber attacks were presented basically as cyber versions of 'pew pew' and 'tech the tech' ie. meaningless technobabble, "The Major is the best at haxoring" but there's no why or therefore or sometimes even any limitations in abilities.