You mean like the Cubs keeping the infield grass long for years? Well...it may have helped them when they were a power running team with Bettis, but it sure doesn't help them now. They have a speedy RB (Parker), a speedy WR (Holmes), and a fast defense. So, I think it hurts more than helps.
It is almost as bad as the old grass a PBS or the "grass" at old Cleveland Municipal Stadium.