Once you've accepted "too many people" is the problem, they will turn to your neighbors and say "X billions gotta go, do you want it to be your families or the global underclass we've spent 500 years teaching you to hate?"
And your neighbors will say "well it can't be ME and MINE, so I guess it's gotta be the global underclass." So you end up literally selling the genocide for the people wanted to do genocides to keep doing capitalism; unwittingly to be sure, but the effect is the same.