The problem with that kind of speculation is you can equally use the same argument against itself. ie maybe they're bluffing people into thinking that the Chinese military / government have been framed as it seems too obvious that it would have been them.
We could also speculate from the angle that the officers in charge of making these decisions are not tech-savvy themselves (or at least not to the level that they might realise just how traceable these attacks), which isn't a huge assumption to make when you look at how incompetent many government officials are who have serious influence over technology policies (eg http://www.bbc.co.uk/news/technology-23437473)
So anyway, my point is it's better to look for a little evidence to support a hypothesis rather than blindly speculate.
We could also speculate from the angle that the officers in charge of making these decisions are not tech-savvy themselves (or at least not to the level that they might realise just how traceable these attacks), which isn't a huge assumption to make when you look at how incompetent many government officials are who have serious influence over technology policies (eg http://www.bbc.co.uk/news/technology-23437473)
So anyway, my point is it's better to look for a little evidence to support a hypothesis rather than blindly speculate.