This is what I said prior to the season. All of Marinelli's detractors didn't want to hear it. "Complicated" schemes are, for the most part, feast or famine. When they work, you look like a genius. When they don't, you look like an idiot.
Real football isn't Madden. You can't just draw something up and expect seamless execution. Athletes, for the most part, aren't thinkers. The more you ask these guys to think, the slower their reactions. In a game where a split second hesitation is the difference between closing a hole or allowing a big run, the less these guys have to think the better.