He would have been better off had he not said anything. He would have been less of a distraction and greatly increased the number of teams who might have been interested. He didn't do it for his own gain. I think he did it to pave the way for the future players to be open about who they are. He put his beliefs over his own personal gain. You may not agree with him, but there is something admirable in his sacrifice.
And I have no idea what it is like for guys like Sam, as a heterosexual. But supposedly living in secret is not something they enjoy.
As for his play, I will bet he plays in a game this year for Dallas. He can play and can fill a great need they have.