alt Hacker NewsLFS is full of packages that fit your description of a black box. It shows you how to compile and configure packages, but I don't remember them diving into the code internals of a single one.
I understand not wanting to shift from something that is wholly explainable to something that isn't, but it's not the end of the world.
No, its not the end of the world. And I agree, LFS isn't going to be the best resource for learning how a compiler works or cron or ntp. But the init process & systemd is so core to linux. I can certainly see the argument that they should be part of the "from scratch" parts.