Off-season with the Cowboys

So there has been some interesting news for Cari today. The Cowboys officially released Terrell Owens and safety Roy Williams today. This means they will have 9 million + 11 million going against them in the salary cap and the Cowboys will get nothing for the money spent. So I believe the Cowboys have about 25 million dollar in dead money going against the salary cap. Boy would I love to get a piece of that pie!!
What I'm confused about is why they didn't try to trade them. We lost 3 draft picks when we traded for the wide receiver Roy Williams (not to be confused with the safety). Even though T.O. has a bad attitude and is just an overall bundle of fun (oh, how the media must love the show he puts on) he stills puts up big numbers. Double digit touchdowns. 1000+ yard seasons. Even if we don't want him in Dallas, somebody will take the chance with him! Speaking of the numbers he puts up, this poses the question: will the other receivers step up and fill T.O.'s shoes in touchdowns and yardage? And Roy Williams was the top receiver with the Lions (much good it did them...), but will he be a top receiver in Dallas (and match what T.O. did) and will that make a difference? Emmitt Smith was still playing for the Cowboys when he was putting up record numbers, but that wasn't reflected in the numbers of wins we got.
Then we have the case of the safety Roy Williams. So he hasn't had the best years lately and he only played like 3 games last season because of injuries, but man I love watching him play. He is a dynamic, hard-hitting player. Maybe his pass defense isn't so great, but who are you going to have step up to do that? The defense is looking to suffer next year... why get rid of a valuable player without trying to trade?
We've lost Chris Canty as a free agent and who knows what is happening with Burnett... I've heard about him and the Raiders... why would anyone want to go to the Raiders??? I've also heard about him talking to the Packers. At least we'll have Demarcus Ware for years to come. Contract is up next year and they're working to make sure he'll be here after that!!
So what's going on with the Cowboys, I'm not sure anyone knows... Last year everyone expected a stellar season, but it was below par. It could have been a lot worse, but such high expectations led to great disappointment. So maybe they're trying to make so nobody knows what to expect so when they win the superbowl it will be as big a shock as the cardinals making it to the superbowl.