I also referred to closeted individuals who will not know that others share their struggles unless they go public. This is a serious consideration. Again, I am not talking about men who are “proactive” about their homosexuality (this is vague but I assume you mean those who have boyfriends and engage in prohibited acts). Obviously such a case is different.
Furthermore, just because someone is publicly violating a mitzvah does not mean they don’t deserve our compassion. I don’t mistreat or cut ties with openly gay men, just as I don’t mistreat or cut ties with Conservative and Reform yidden. To do so would be a tremendous chillul Hashem, and would only drive the person further away from yiddishkeit. “Coming out” is a cry for help, and if our response to it is to castigate the person or, worse, shun him, he will certainly not be motivated to do teshuvah.