The team doctor for my son's high school football field is a biogeneticist. (He just left for the Antarctic to study micro-organisms than live in saline lakes under permanent ice caps.)
He absolutely hates artificial turf on football fields, which is becoming ever more common in high school football. He believes that the growing problem of staph infections among football players, such as Peyton Manning, is exacerbated by artificial turf. Traditional grass fields host an extremely rich and diverse ecology of micro-organisms. New germs can't take over a grass field because there are so many competitors already there, some of whom will eat them. And we've evolved to deal with the typical kind of germs living in grass -- humans have been messing around on grass for a long time.
In contrast, artificial turf is an ecological desert. There aren't many competitors for staph germs. So, if one kid with staph scrapes some of it off on the turf and then another kid lands on the same spot and gets a turf burn, the second kid can get a staph infection in his bloodstream.
Anyway, that's his theory.
My view is that in the 37 years I've been playing golf, greenskeepers have made lots of progress on keeping grass healthy. (They even have a golf course grass today that doesn't need freshwater -- you just spray salty seawater on it pumped right out of the ocean.) Is it really that hard to keep a grass field in decent shape? If you are thinking of putting in expensive artificial turf, why not instead put in the kind of super drainage that can keep a field from getting chewed up when played on in the rain.
And I'm not sure that I really like the kind of Peyton Manning-style football that evolves on artificial turf. You can make the passing game much more precise on artificial turf (especially indoors) because the receiver's footing is absolutely consistent -- if he executes correctly and the defense doesn't get in the way, he will be at spot X in Y seconds every time because there's no missteps.
But you'll notice that Monday night games in the snow get higher ratings because football is not supposed to be all that precise.