Point would be that if you have kids you have skin in the game and would make more responsible choices with your vote. Same has been said about military service, which also makes a lot of sense. Not practically, of course, but the point highlights the fact that we could have people who are unqualified to make decisions, even if its electing officials, making decisions that impact everyone, including and maybe more importantly, the generations to come.

In a true democracy there is no mechanism for qualifiying or handling quality control for the voting population, and so for elected officials and their policies. This is why we are a democratic republic, and Elon is just saying if you're going to be involved in electing officials you should have skin in the game.

We already have requirements to voting and if you think about it, they are in the same spirit.