as they did in the sixties (quoting as best I can remember), "Football is about blocking and tackling. I don't care about trick plays and fancy formations. If you can block and tackle better than your opponent, you will win."
Kelly is a system coach and all system coaches seem to suffer from the same flawed paradigm...they think their system is more important than fundamentals. What they fail to grasp is, without execution, the system won't work and execution is the result of sound fundamentals. Charlie Weis is also a system coach.