I don’t consider it a defense, exactly. It’s more clarification. Just saying “no kids” might suggest he doesn’t want kids ever, which would reduce the potential partners unnecessarily (and if he does want kids eventually, being paired with someone specifically because they don’t want kids would just create problems later). Saying “no kids yet” sets them up with someone who doesn’t have kids but might in the future.
Even if that were true, which is truly ridiculous, new factions would pop up. If it swayed so far left that the Democrats always won, all the further left people would demand all the things they’ve been left without just to keep fascists from winning.
Basically, it would just be a leftward shift of the Overton window, which is LONNNG overdue. But it certainly wouldn’t be the end of elections, that’s stupid.