Being who they are

Does as person's sexual orientation constitute who they are? I am a lot of things. I am a Christian, I like the
Cardinals and the Suns, I teach at ASU West, I am a Democrat, etc.  And I happen to be a heterosexual. People who think there is something wrong with homosexual conduct say that disapproving of homosexual conduct isn't the same as hating homosexuals. In response, defenders of homosexuality will them say "You say you accept homosexuals as people, but you are opposed to them being who they are." But doesn't that assume that your sexual orientation is constitutive of who you are in ways your other activities are not. Is being gay or being straight an essential property of a person? 

It is interesting when conservative Christians say that they only oppose homosexual activity and not homosexuals, they are criticized. Sometimes this is a matter of Christians not living up to the "hate the sin, love the sinner" rhetoric. But sometimes it is suggested that this response doesn't make sense because being gay is "who they are."Yet the same people who say "this is who they are" will sometimes say that hate Christianity but not Christians. Why do these two things mix?