Comment by cloogshicer

I don't think that Naur was arguing that it has to be a single developer who knows everything. It could also be multiple developers, where each one of them has loaded a sub-problem of a bigger problem into their head.

Usually in OSS projects you have a handful or so of contributors doing the bulk of the work, right? Imagine them all going away at once for one of those projects you mentioned. I feel the project would be in pretty bad shape.