Shhhh don't tell the Smel that, he might think its not the '70's anymore
The field is too small for today's players. It's the same size as when the Cardinals starting Center, a first round pick and 2 time pro bowler Ki Aldrich was 6'0 207lbs. Paddy Driscoll played on the same sized field and he was 5'11 160lbs. And he's in the Hall of Fame!
Now we have 6'3" 250lb guys who run 4.5 forties!
That's why the NFL has rigged the rules to promote the passing game. It's also why College teams have gone to the spread offense. Except in the SEC where they only have to score 6 points to win. There just isn't enough room to run the football.
Same thing for basketball. Today's players are so big and athletic that without the 3 point shot no team could even run an offense.