For what it matters, here are my reasons for not having children. And yes, I'm in a heterosexual relationship and it was possible for us to have children but chose not to. The world is fucked, I couldn't bring a life in to this world where we are killing ourselves and the planet. Where the day to day is to hope you make enough money to just survive. We humans are selfish and fearful creatures. It's a gross world we live in.
Someone will come along and say, who will take care of me when I'm old? When I get close to that point, I'll follow Hunter S. Thompson's lead.
Seriously, I watched my grand parents slowly decay over the course of 15 years, it was not life.
If our primary goals as humans was to learn, create, explore and preserve; I would probably have a big fucking family because I would want my children to share in that.
Rather, we deny, horde, kill and build walls.