Historically some people wanted to keep their sexuality private because they felt they might lose sales / votes / whatever if people knew their sexuality.
Don't forget that homosexuality has only relatively recently become legal in England.
The Jason Donovan case is particularly interesting.
Hopefully these days you couldn't be because nobody should care.
But if you were running say a local paper and you went out of your way to consistently describe a local politician or school teacher/principal as "the homosexual Mr Smith" and your intentions were malicious they could have a reasonable chance of damages from you.
Don't forget that homosexuality has only relatively recently become legal in England.
The Jason Donovan case is particularly interesting.
(http://www.independent.co.uk/news/sad-about-the-boy-1270092....)
(http://en.wikipedia.org/wiki/Jason_Donovan)
(http://www.guardian.co.uk/world/2000/apr/17/law.claredyer)