You're more than free to do with your own time what you wish. These projects aren't harming you in any way. Who cares what enthusiasts want to do for fun? They're not trying to supplant the OS on your desktop. They're learning something and having fun doing it. I love these sorts of projects.
In contrast, many of us treat computers as a magic black box. The abstraction is great for productively building web apps. But, we've lost sight of how things work and I think that's led to steep decline in performance and, perhaps, security. I don't pine for manual resource management in all things, but knowing how syscalls work can help build context on when and why you should use them. Revisiting how to build an OS that isn't rooted in decades-old Linux or BSD code could be really instructive.
In contrast, many of us treat computers as a magic black box. The abstraction is great for productively building web apps. But, we've lost sight of how things work and I think that's led to steep decline in performance and, perhaps, security. I don't pine for manual resource management in all things, but knowing how syscalls work can help build context on when and why you should use them. Revisiting how to build an OS that isn't rooted in decades-old Linux or BSD code could be really instructive.