As in every country throughout history, Turkey has LBGTQ communities that make their contributions to the richness and variety of Turkish society.
Also, as in many countries and societies throughout history, legal restrictions may limit the freedom of people to express their preferences and personalities, so discretion may be a virtue for LBGTQ visitors.
Progress is being made toward understanding and mutual acceptance, but the majority of people in Turkey are relatively conservative and want male-female relationships to be the only ones sanctioned by society.
Other relationships exist, of course, as they always have, but are not sanctioned, are practiced in seclusion, and are mostly not publicly acknowledged.
Being straight as a minaret, I have no personal experience with the gay scene in Turkey, but a good travel agency serving both gay and straight travelers is:
—by Tom Brosnahan