Because we stereotypically prefer female vocals and are more in tune with our feminine side than straights so we are drawn to all sorts of arts. Hence why it's mostly musicians. Straights tend to have their icons as well and it's mostly athletes etc. even thought it's a stereotype I think it holds water.
There aren't many prominent gay people in the media to identify with - especially not over the past century as a whole
instead we identify with women, a gender which has a lot more emotional freedom and expression than men - something LGBT people crave, after feeling oppressed
Because there aren't enough strong male LGBT activists. American men lose their manhood if they over support the cause. One of the million things wrong with this country.
Because strong, confident women of power who support them (and other women) intimidate straight men all over the world which is something gays want to feel, as they are often insecure beings who feel trapped.
Also, women sing about their sexual desires towards men, as opposed to men singing about their sexual desires towards women. Gays relate to women in this aspect.
Because G.U.Y.s don't want their image to come off as "gay" if they support us, which is ridiculous but unfortunately society dictates even through blind ignorance
