See, here's where you (rhetorical) keep running into the same logical falllacy again and again and again and again and again:
African-Americans reproduce. Europeans reproduce. Tall people reproduce. Dwarves even reproduce (kinda hit & miss, but often enough for multi-generations).
Gays do not reproduce.
Oh, sure, they can biologically produce offspring, and those offpsring or offspring they've adopted are extremely likely to grow up sharing their parents' views on tolerating homosexual behavior.
But the children are no more likely to be actual homosexuals themselves than any random dip in the gene pool.
In this sense, gays are like Christians: They can not biologically produce a new generation of their own kind, they must recruit others in.
In the case of gays, they need to persuade those who have phsyiological and/or psychological leanings towards homosexual behavior to embrace the self-defined gay lifestyle. With Christians they must educate their children then do evangelical outreach to share the good news.
The difference between the gay sub-culture and (to pick just one example) African-American sub-culture is that the African-American sub-culutre is spread through multiple biological generations. There are genetic lines going back hundreds of years even if the names of the people on those lines have been lost to history. There are families and interlinking relations that permeate the entire culture.
Gays have no bloodlines in the sense of homosexual orientation. Yes, gays are members of family trees, but their "gayness" is an apparently random mutation that does not breed true.
Remember the dwarves (or, as many prefer to be called now, little people) I mentioned above? If two dwarves marry, there is an excelent chance they will produce children who are dwarves. If they can trace back two or three generations of dwarven parents, the chance for their offpsring sharing those traits is virtually guaranteed. (There are instances -- and I know one such family personally -- where one or both parents had mothers or fathers who were of normal height, and as a result some of their nchildren are born with dwarf genes while others are born with normal height.)
There is in the little people community, in fact, a far better example of a sub-culture than among the gay community.
Each gay generation dies out.
They do not produce a new generation of gays.
Even if they give birth to biological children and/or adopt, those children have no more chance of becoming gay than any random selection of human beings. The gays' children will not be gay themselves, and their offspring will be no more likely to be gay, and so on and so on.
Homosexuality does not breed true.