I really don't think it's as cut and dried as "these people ARE gay, and must come out".
First of all, in a culture where celebrities can't go out for a packet of cigarettes without spending 3 hours in makeup, or else their photos get splashed across every gossip magazine in circulation with a ring around every blemish and line. These people are doing a job, and getting paid handsomely for it, but does that give us the right to demand full disclosure on every aspect of their lives? I don't know about anyone else, but when I finish work for the day, I want to kick my shoes off, wear my slobby round the house clothes, and not have to worry about how I look, what I say or whether or not I fart. If I tramp outside looking like shit to take a bag of rubbish out, I don't want to see 5 of my clients standing at my front door asking me to design a flyer for them. Give the people their right to have a private life.
Saying that, if someone whose opinion matters, like a politian or role model, publicly condemns a practice or lifestyle that they are secretly involved in, be that alcohol, drugs, sexual practices, then that is a matter of hypocrisy. I was watching a program on television the other week about gays in the UK government, and how currently the feeling is that it doesn't matter whether you choose to come out or not, but if you're gay and you're voicing anti gay policies as a good thing, it's gonna bite you on the arse.
In the alternate reality where I became a celebrity tomorrow, I would not be rushing to tell the world that I was gay. Why? All my friends know, my parents and siblings know, I'm very comfortable with who I am. However, there are members of my family would have a hard time dealing with it, and we've decided it's best for them to be left in the dark. If a situation arose where I felt I could not speak out against it without coming out first, I would have to consider that then, similar to George Takei, Sulu from star trek. For years he'd never publically came out, but then with all the fever about gay marriages, he felt he wanted to throw his hat into the ring, and came out in order to do so. To speak out against what the local government was doing without stating that he himself was gay was, in his opinion, pointless.
Also, bear in mind that on this site we recognise that things are not as simple as "gay/bi/str8". We have a percentage system to demonstrate this. Why then are celebrities automatically dubbed as "gay", even though they may have done nothing more than all the people here who would refer to themselves as 99% straight, but have had same sex experiences? Is that hypocritical on our part?