Given that much of the criticism of systemd is based on, "it's not like Unix," that certainly seems like enough of a reason to me. People would complain even more if systemd required a custom library to install your bootloader than they do when calling rm -rf / on a system without GNU extensions (--preserve-root by default) bricks a motherboard.
FreeBSD uses a library and I don't think it suffers from criticism that its not UNIX. UNIX isn't Plan 9, and exposing something that can brick your system in the filesystem is just irresponsible. You can blame the vendor, but it should have never gotten as far as the vendor's bad decisions.