Um... none of those guys would be starters on the 2008 Dallas Cowboys.
We rid ourselves of a large amount of cap space moving those players (especially Ferguson and Ayodele), players who would NOT crack our starting lineup.
The need for Ayodele (one of our very worst defensive starters in 2007, and a guy who would NOT see time as a backup on the nickel or dime) is minimized with the Zach Thomas acquisition, and the need for Ferguson is non-existent with the emergence of Jay Ratliff and the potential of Tank Johnson (who we are paying pennies for).
Ferguson likely wouldn't even be our 2nd string NT if he were here, and look how much he is due to make in 2008.
The trades worked out beautifully for both the Dolphins AND the Cowboys, unless if you think it's a GREAT idea to pay a bunch of money to backups who will hardly ever see the field...
But it's not surprising that casual fans would look at it and simply see the names switching teams, and think, "They screwed us!!!"