It's because people want to test whether their command is actually successfully executed by cron because basic functionality like starting a job immediately isn't available and then they forget to revert that change.
You have to use systemd timers for that... It's completely overkill (2 files each with a dozen lines) but it works much better in practice.
I don't think that's the problem, I just think its really easy to forget to set it to 0. I literally lol'd when I just happened to be reading the docs here just now: https://rancher.com/docs/k3s/latest/en/installation/install-... and saw it under the example cron for "--etcd-snapshot-schedule-cron."
You have to use systemd timers for that... It's completely overkill (2 files each with a dozen lines) but it works much better in practice.