The player's union is alleging that Barry Bonds has not been signed because the owners conspired together to not sign him. Personally I think it is a case of nobody wanting to sign a player who has burned too many bridges behind him. His agent Jeff Borris says that he hasn't received an offer of any amount since Bonds became eligible to be signed as a free agent.
I doubt that the owners would combine forces to keep Bonds out of baseball after the owners were forced to pay $280 million in 1990 for collusion. Bonds has simply worn out his welcome in major league baseball. There has not been a sinister plot to keep him out of baseball. Bonds is not a team player and that as much as anything has kept him from being signed.
Anytime a player like Bonds expects and gets special treatment there is going to be resentment from the other players. Another reason is that teams don't even want to talk money with Bonds and his agent because his asking price will be a lot more than he is worth unless Bonds is so desperate to get his 3000th hit he would ask for a paltry sum to play in 2008 at some point in the season.
Bonds may help a team as a designated hitter but he is subject to injuries that would not even let him play in the American League if he can't bat. If a National League team were to sign him I would be in complete shock since his fielding has been progressively worse every year and he doesn't have the wheels to run down fly balls unless they are hit directly to him or in his immediate vicinity.
Another major reason a team would not want to sign Bonds is the perception that he has used steroids which is 99.9 percent certain and by signing him they are condoning his using steroids. There may be a team that is desperate to sign Bonds but I can't see that happening. If they do buyer beware. The main selling point Bonds has is his .480 on base percentage of last season. For a team having trouble scoring runs he could make a difference. The season is close to 25 percent over and I think the teams are finding out major league baseball can survive without Bonds.