It's not just the turnovers, although it's hard to win when you're giving the other team the ball.  It's everything.  Kicking, punting, special teams coverage, blocking, penalties... the list goes on and on.  It's painful to see this defensive unit play well enough to beat most teams if they'd get just a little help from the offense.  All of this isn't on Siemian.  I think he's a capable QB, but he isn't a special playmaker type.  He has taken a beating and he has little pocket awareness.  Give him time and he'll show you something.  Blocking aside, the coaching staff doesn't seem to be either willing or capable of altering their offense around what they have.  I see no aggression offensively.  Instead, they're trying to hang on and play safe.  It isn't working.