That seems overly simplistic, given the diverse claims as to the nature of God/Gods.
To pick one, the Judaeo-Christian god seems to be unwilling to allow proof of its existence. This seems to be intentional, to place the acceptance/rejection of its existence onto a plane of personal faith, rather than provable fact.
" I should prioritize my own over the rest of the world"
It feels like you're suggesting that a job such as SpaceX is automatically beneficial to the rest of the world.
I suggest that you are assuming too much. Could SpaceX usher in a golden age of transport and colonisation? Sure. It might also fail.
I suggest that you are also assuming too much by suggesting that parenting your children is selfish and (implicitly) doesn't benefit the world. It's possibly that SpaceX takes us all to Mars and none of the kids/descendants of its employees were ever going to achieve world changing things without their mum/dad being around more. It's also possible that some of those kids would have achieved greatness if only they had a more present mum/dad in their life.
You can't bail the future down, it's made of unrealised possibilities that we make real with our choices. Those choices are either implicit or explicit and we have no way of knowing what will actually happen.
You might not care, RMS might not care, but please don't assume that "no one else cares". I don't know you, and I don't know RMS, but he doesn't seem like the most emotionally intelligent person, perhaps you aren't either. Nothing wrong with that, you are who you are.
Some people are capable of responding very strongly to the emotions of others. I'm not saying they're better than you, just that they're different to you, and that they exist :)
Ok, I might overstated it for dramatics, but what I'm complaining about is that being considerate should go both ways. I'll be happy for you that you have a kid and congratulate you, but please don't assume that it's in any way as important for me as it is for you.
It reminds me a thing my friend told me once, that she sometimes wonder whether if she'll have a kid, will she be as obnoxious about it on Facebook as many of her friends.
As a maintainer of a Mjolnir fork (Hammerspoon), I take your point that there are very many options in this space, but IMO that can be a good thing - lots of exploring in different directions can help us figure out what works well for people :)