I _don't_ like the idea of crontabs in /etc, because that means joe
random user can fill up my root partition.  (They can fill up /var
easily enough using /var/tmp).

In general, I don't want anything that grows over time or is
user-writable to be on my root file system, crontabs included.

My personal model is that /var is for system-specific stuff that I don't
want on the root partition and isn't appropriate for a shared /usr.  Of
course, this model probably doesn't match the core team's model for
/var.

==John