Why gay pride?

It is fifty years since the laws regarding homosexuality were repealed in 1967 and quite right too. Many men and women suffered terrible abuse then and for many years after after since the stigma remained. But now, with many from all walks of life including sportsmen and women having 'come out' there seems to be a mood of confrontation; dare I say it a challenge to straight people to deny them their sexuality by parading in what seems to me to be a sort of 'freak' show.
The London gay pride celebration has been held drawing vast crowds to their march and exhibitions; but why do they do it? Why draw attention to their condition in this provocative fashion? No one can doubt their right to celebrate but what exactly is it they are celebrating so publicly? We don't have (as far as I know) 'straight pride' carnivals, sinistral pride parades, a celebration of left handers or perhaps monoped pride for those pleased to demonstrate their skills and prowess on one foot. No the LGBT lobby is flexing their muscle most decidedly in several ways including political, no more so than in the sphere of religion. Pressure is on the Anglican Church to allow the marriage of same sex couples in their churches contrary to canon law, because gay couples feel stigmatised by being unable to complete their vows before God and their peers. This despite being allowed to formalise their relationship in a 'civil partnership' which shares the same benefits and obligations as a conventional marriage.
But, marriage is an institution ordained by God allowing men and women to be joined and blessed for the purpose of begetting issue. It was never meant as a vessel for same sex couples, even if they intended to foster children, so why is it that some gay couples want to join a club to which they do not qualify when so many of the club members are against the idea? I could never understand why women in particular wanted to join men only clubs such as Muirfield Golf Club. I have never met a man who wanted to join the Women's Institute. Perhaps the gay community are pushing it in vengeful reparation for the horrible things said about them in the bible. Perhaps they think they are owed by the Christian community.
There is no doubt that the number of people coming out has surprised some people; not only homosexual but transgender and bi-sexual, reinforcing the view that gender identity has more diversity than previously imagined. This, however comes as no surprise to me because The Davies Hypothesis demonstrates how gender identity is manifest in inherited character.