Wenger himself has made a nonsense of the expectations argument. It's him who says every year that Arsenal are good enough to win the league.
It's not that Arsenal haven't won the league in 12 years though, it's the mind numbing predictability. Hlebs got slated for being negative at the start of the season when we were doing well but guess what, he got it spot on. The league campaign has been exactly the same for over a decade. The CL campaigns are getting worse. Wenger just isn't able to do the job he used to be able to. Performances aren't as good, signings aren't as good, mentality is poor, there's no leaders. He just doesn't appear able to fix the problems.