The biggest argument people seem to have is that "users who are not tech savvy won't remember to log out". Quick wake up call: users who aren't tech savvy don't know what "remember me" really does, and chances are they see it as a "don't make me log in again" option which they will always prefer, even if it's not as secure.
Typical users don't have a concept of security, they only want convenience.
Typical users don't have a concept of security, they only want convenience.