How are these guys still at home? Best available free agents

I thought I would compile a list of free agents that are still sitting at home and see if you agree with me, that some of these undrafted free agent guy should be on a roster before these guys? I checked their names, I don’t see any of them on a roster, if they are let me know so I can remove them, but there are still some solid guys at the house. 

Quarterback 

Rex Grossman 

Running Backs

Bernard Scott
Ronnie Brown
Willis McGahee

Fullbacks

Le’Ron McClain
Greg Jones
Vonta Leach

Wide Receivers

Santonio Holmes
Danario Alexander 

Tight Ends

Dustin Keller
Kellen Winslow
Ben Hartsock

Offensive Tackles

David Stewart 
Bryant McKinnie
Ryan Harris
Eric Winston
Levi Brown

Offensive Guards

Brian Waters
Richie Incognito
Daryn Colledge

Centers

 Samson Satele

Defensive Ends

Brett Keisel
Andre Carter

Defensive Tackles

Ryan Pickett
Johnny Jolly
Aubrayo Franklin
Isaac Sopoaga
Gary Gibson

Outside Linebackers

Adrian Hamilton
James Harrison
Erin Henderson
Stephen Nicholas
Michael Boley
Ernie Sims
Marvin Mitchell
Will Herring

Inside Linebackers

Pat Angerer
Desmond Bishop
Jonathan Vilma
Paris Lenon
Nick Barnett
Bryan Kehl
Will Witherspoon

Cornerbacks

Terrell Thomas
Asante Samuel
Jabari Greer
Drayton Florence
Dunta Robinson

Safeties

Steve Gregory 
Nick Collins
Yeremiah Bell
Kerry Rhodes 
Ed Reed
Jim Leonhard

Kickers

Rob Bironas
Rian Lindell
David Akers

Punters

Mat McBriar
Zoltan Mesko 
Sav Rocca