Is gay liberation leading to gay genocide?

Look at this graph (GSS data) which shows the mean number of children that gay men ages 40-64 have for the past four decades:

In the 80s, the average gay man had two kids.  By the 90s, the number had dropped to .81, and in this decade, it's down to .58.  In other words, a gay man 40 years wasn't that different than a straight guy in terms of offspring. Now, he has less than 30% the family size of a heterosexual.

While Greg Cochran is right that the heritability of homosexuality is not high, there seems to be some genetic influence, so it's ironic that gay liberation is leading to fewer people with genes that raise the odds of homosexuality.  That implies fewer and fewer gay men in the future.  Strange, but I don't hear anyone accusing liberals of secretly pushing for the slow genocide of homosexuals.