''As a personal note, I do not like this decision. To me LFS is about learning how a system works. Understanding the boot process is a big part of that. systemd is about 1678 "C" files plus many data files. System V is "22" C files plus about 50 short bash scripts and data files. Yes, systemd provides a lot of capabilities, but we will be losing some things I consider important.
However, the decision needs to be made.''
If the project is even split in different parts that you need to understand... already makes the point.
To make an analogy: another part of LFS is building a compiler toolchain. You don't need to understand GCC internals to know how to do that.
The attitude that you don't need to learn what is inside the magic black box is exactly the kind of thing LFS is pushing against. UNIX traditionally was a "worse is better" system, where its seen as better design to have a simple system that you can understand the internals of even if that simplicity leads to bugs. Simple systems that fit the needs of the users can evolve into complex systems that fit the needs of users. But you (arguably) can't start with a complex system that people don't use and get users.
If anyone hasn't read the full Worse Is Better article before, its your lucky day:
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.
They still explain what an init system is for and how to use it.