There is every reason to have a day against homophobia and transphobia: 80 countries in the world consider homosexuality illegal, 5 of them punish homosexual acts by death.
We don't speak about Armenia even. It is not illegal here and there is no punishment by law but still society and authorities are homophobic, they have their methods to punish those people.
Such kind of fears and phobias are result of acknowledgement and lack of information.
picture source: www.unconditional-self-acceptance.com