Its because it takes longer to say:
"Fitz, you line up on the cheerleader side of the field, run down to the blonde and then cut for the bald ref. Quan, you run as fast as you can about 6 yards then cut over the middle, try to wave so I'll see you. Bryant, you just run as fast as you can down the sideline opposite Fitz, but remember to keep looking back at me all the way, you never know when I might have to throw the ball. Edge, you sneak through the pass rush to just beyond where Step falls down, turn around and smile, so the gleam will catch my eye, in case I can't see anything else. Milford and Reggie, you're going to be the red herrings on this play to confuse the defense, Mildford, you pull left, Reggie, you pull right.
Step and Big....the snap count is on "2", that comes right after "1". Oliver, rememeber that DE in front of you needs to be slowed down as he's been trying to rip my head off every play. Leonard, after you pretend this is a screen play, and after your man jets by you, you run a 10 yard slant over the middle, if the ball is anywhere near you, you try and tip it to Quan or Fitz, or if they aren't around, to whomever seems closest. Adam, what are you doing here in the huddle?
Any questions? OK, lets all meet at Denny's for a chili dog after the game. I got approval to put it on the team tab. "
Than, "Edge, I'm gonna give you the ball, run like your life depends on it".