I think what you have is a very good team with a serious flaw; I really think it's that simple. Some teams can exploit that flaw and others cant so you get these odd results. It's just not a matter of having a bad day (although every team has them) it's not even really a design flaw, it's just there are a couple of players who are simply not good enough in their assigned roles.
So, its been a wormy and weird season; not horrible but no where good enough for this team. It's fixable but its going to be an odd transfer market so we'll just have to see if they can make the signings they need to in time to integrate them into the team to be able to do better next season.