One reason ... the ability to search for Historic players.
Examples:
Browns
Bernie Kosar
Brian Sipe
AND MORE
Chiefs (for you Chiefs here)
Elvis Grbac
Steve Bono
AND MORE
Raiders
Cole Ford - he tried to kill those guys in Vegas
Lamonica - for good measure
AND MORE
Chargers
Ryan Leaf
Stan Humphries
AND MORE
Broncos
Some Guy Who used to be their QB
Steve Watson