Gender, Sexuality and Its Expression My previous response was in reference to your mention of the male stereotype of masculinity and what it means to be a man. Individuality and masculinity, versus collectivity and lgtbq. Of course, the person you reference is following his/her own individual instincts, but would not have a critical mass of similar people to become the dominant culture so has to depend on collectivity and popular movement.
Regarding the second paragraph you wrote transphobia likely comes from individual sexual preference. Individuality I believe, even though it is the root of transexuals identity, is against them and lgtbq because majority individual sexual preference is heterosexual, and individuality is not to play nice with others, can be hurtful and insensitive to others. This is because individual communications are not meant to join people together, but to keep separate. Insulting and being mean and abrasive is very individualistic, whereas collectivism involves understanding and forming bonds with others.
Regarding third paragraph, it is a tough question. I think each person expresses instinct. Although, the way instinct is defined and talked about, denies it plays a role in human behavior. But I believe instinct, or something like it is the basis of sexual behavior, but ultimately the culture it produces is going to defend those instincts. I think whether someone is more individualistic or more collective is also instinctual, like being introvert of extrovert or conservative or liberal, and that influences how people will be swayed by the cultures produced by competing instincts.