Your reasoning is sound, but is already covered by Collapse OS' manifesto. It refers to two stages of collapse, Collapse OS being for the second.

As long as we have working modern machines, self-contained modern open source OSes, NetBSD being one, are good choices.

One problem there is with such system is their overall complexity. Sure, you can use them, and they're pretty flexible for the user. However, when necessity forces you to crack the kernel open, the learning curve is pretty big.

For example, let's imagine a computer with a broken SATA controller. How would NetBSD behave on it? Hard to say, NetBSD developers don't develop with that target machine in mind. Usually, when you have such a machine, you replace it or repair it. But what if you can't? Maybe you'll have to play in the kernel to manage to do something with that machine, route around it. Maybe it will work, but maybe you'll be stuck, and maybe that in that particular situation, it's going to have tragic consequences.

And that's kind of what Dusk OS (http://duskos.org/) is about.