People usually out themselves ,before the press does it for them with all the sleaze etc that they can hang onto the story to sell papers.
Being gay and in the so called closet isnt easy, especially for people and sportsmen in public life, for some bigots theyre still seen as a good whipping boy, or figure of derision, the word queer used to be a derisory word, now people like Peter Thatchell use it as a reverse insult, branding themselves as queer.
Also people need to ask themselves would they still get changed in front of a gay mate, or somebody they didnt know,who was gay in a comunal changing room, if the answer is no, ask yourself why, especially if you see nothing wrong with being gay.
Thats possibly one of the reasons why people dont out themselves.