With a small amount of research I have discovered that since 1900, one hundred and fourteen years in total, there have only been 24 (twenty-four) sports people in the British Isles who have been our or come out as gay.
Document:    Sports people who have come out in the British Isles
So why don’t sportsmen and sportswomen ‘come out’ if they are gay?  Of course there is no reason why someone has to announce they are gay, there is no law, no contract (indeed there may even be contracts preventing it); but, with so few sportsmen and sportswomen visible who are gay, then those growing up don’t have positive role models to aspire to.  It also enables the continuing stigmatisation of the LGBT community.
John Amaechi, the British basketballer said ‘…people have a misconception that time will automatically bring progress and that homophobia is in the decline … if you’re associated with a word that has so many pejorative connotations – ‘gay’ regularly used to mean bad, weak, wrong, sinful – it’s going to affect you’
History has shown that gay women in sports are more routinely accepted than men; but even they have been the target of bullying on and off the field, in society and in the media.
Gay men in sports are stigmatised more because being a sportsman means you are rough, tough and a ladiesman.  If you are gay you can’t be a great sportsman.
Secondly, all spo0rtsmen and sportswomen depend on sponsorship, and the sponsors have not necessarily bee supportive of equality and freedom for LGBT athletes.
 
As I referred to at the start of this article, there are 24 noted sportsmen and sportswomen:

• 4 in the 1990s
• 5 in the 2000s

And

• 6 so far in the 2010s

Hopefully the tide is turning and society is more accepting, also the establishment which controls the laws and the purse strings of so much sponsorship.
What will be even more interesting is to watch and review the Winter Games in Sochi, Russia during and after the event in relationship to both the athletes who are LGBT and who go there and perform, and also for the local LGBT groups and individuals who are suffering persecution through the new laws and trumped charges and arrests.
Premier Putin’s homophobia has been shown up repeatedly, and the Mayor of Sochi (Anatoly Pakhomov) would seem to be equally homophobic ( or is he just securing his political position?) – his latest speech stating that there are no gays living in Sochi only further highlight’s Russia’s perilous states for LGBT people.