How does one create a Unix-derived operating system that deprecates cron? That's like deprecating ls or man or sendmail.
Same way a Unix system deprecates
vi in favor of
vim, or
rsh in favor of
ssh. When you have a superior tool available, discourage use of the old inferior tool.
OK,
vi and
rsh are still there, and haven't been officially deprecated (although
rsh should be), but files like
/etc/passwd or
/etc/rc are either gone or only a shadow of their former selves. Even Unix sometimes lets go of the past.