Because Arch makes you do everything, the answer to why it broke is always you.

There was an unofficial motto to that effect at one time.

Except when it's not, and the answer is the maintainers [1].

[1] https://bugs.archlinux.org/index.php?do=details&task_id=5051... (hit this myself a couple days ago)

Nowadays, the reason why it broke is either you, or Systemd. But the reason why your system has systemd is that you didn't uninstall it.

Your system might have also broken because you didn't read the RSS feed, which warns of potentially breaking changes.

When in doubt, blame yourself. Or Alan.