They do, just never at rates that are come close to the straights, because it is a whole thing one has to set out organise (usual caveats about exceptions, notwithstanding).
I guess incels believe that they have a lower chance of procreating than the gays.
Until they relinquish their noxious views, they're probably right in that belief, but I'd imagine this guy & his associates are referring not to procreation, but to shifts in the social hierarchy.