The Cowboys were 26th in passing last year with Dez and they're 29th without him. It's not as if the drop was from 6th to 29th. It was poor with him, and it's poor without him.
One, maybe two teams, offered him a contract. There are 31 other teams in the NFL besides Dallas. It seems a lot of other teams don't see him as a difference maker, or simply see him as more bother than he's worth. It's not as if the Cowboys were the only team who saw him pout with the season on the line vs Seattle, then set fire to the Star after he left. That he's even still available in October speaks volumes.
20 more pages of posts by the Dez Fan Club won't change any of those things.