I think there's a very important distinction to be made here. Having kids and taking care of kids you already have are too very different things.

If you're calling not having kids selfish, that's just completely weird. You are going to have to prove first that your opinion isn't also one of these invented ideas.

If we're talking about taking care of them, I kind of agree. Excluding extreme circumstances like rape in a country without abortion, you kind of know what you're willingly signing up for when you have kids. You forced them into the world, they are your responsibility.