The fact that the Bills could not offload Parrish does speak quite a bit to his "usefulness" .
Also, as much as you would like to cite Parrish's returns, how many times a year does he actually do that what you linked in You Tube? Does his 1 return for a TD every year actually make a difference in the scheme of things? Has he done it this year? Maybe you should also link the videos of Parrish having critical fumbles or giving away the Cleveland game. How about that time he gained -20 yards of field position?
I'm looking at the current PR stats and it shows Parrish with an awesome 6.1 yd average , which puts him 21st in the NFL among punt returners. Awesome indeed.