As it's ASSUMED that the world is and should be heterosexual - which is EXACTLY why its important that the LGBT community DO stand up and both claim LGBT people from history and that we flag up that LGBT people DID and DO exist and our existence shouldn't and cant and wont be allowed to be hidden. Nor can it be brushed away or hidden behind a veil of straightness just to suit the continues straight history / lets pretend that LGBT people didn't exist / are all bad agenda . That is what PRIDE ( amongst other things) should be all about surely !
For example even from the most cursory Google search ( which actually gave up very few genuinely useful results surprisingly - which says a lot in itself !) but even the most basic search of "famous gay people from history" gives the following list of people for starters ( or course there are SO many more, I'm just using this list as an example). So, can ANY one of us HONESTLY say that at school that we were taught that these people were or may have been gay!?? And if so was / would that info have been presented to us in a positive LGBT reaffirming way or even at least just as a mere statement of fact.....I honestly doubt it ?
So, yes we SHOULD ask ( if there's reason to) and be happy and proud to claim back LGBT people and their achievements so that younger LGBT people coming after us realise that yes, it IS OK to be gay, just as many many people who came before them were.
That short example list included the likes of
Leonardo da Vinci
Florence Nightingale
King James VI and I
William Shakespeare
Richard I
Julius Caesar
Aristotle
Alan Turing
So, were any of us taught that these people were gay when at school - and in a positively reinforcing, factual way ( and due to the ages across the board we can't ALL blame Maggie Thatchers horrendous Section 28 rule for that I'm guessing here by the way)? I somehow doubt it ?