No need to. The hetero population produce a never ending supply.
Don't you just LOVE how they always seem to be laboring in ignorance of that basic OBVIOUS fact--that the gay people that exist NOW didn't universally (probably MOST of them didn't) come from gay parents (either by adoption or some sort of artificial insemination and surrogate process).
Depends on who you call "they". You can use artificial insemination, you know?