I also have to disagree.
Football is one of the most complex games people play. Each play is a choreographed ballet where the dancers weigh 250lbs and up.
If you watch the slow motion diagrams of the plays showing how everyone moves you get a real appreciation how these oversized behemoths have to move in unison.
most sports have designated specialty players. Thats not necessarily a flaw, imho.
Check out Olympic hockey to see how time should be used efficiently in a team sport. They have 60 minutes of play and two 15-minute intermissions to clean the ice, and the average hockey game has around 55-65 stoppages of play that require a faceoff ... and they get through that all of that in about 2 hours and 15 minutes.