default zfs layout - FreeBSD 11.0 - /var and /usr not mounted ?!

[Rudy]

I installed a new system and did the default ZFS layout and noticed /var 
and /usr are not mounted by default.  Any reason? Seems like files 
dropped in /usr (eg, usr/local) end up in the ROOT/default.  Maybe I am 
just thinking about ZFS incorrectly...

 > zfs get mounted
NAME                PROPERTY  VALUE    SOURCE
zroot               mounted   yes      -
zroot/ROOT          mounted   no       -
zroot/ROOT/default  mounted   yes      -
zroot/data          mounted   yes      -
zroot/tmp           mounted   yes      -
zroot/usr           mounted   no       -
zroot/usr/home      mounted   yes      -
zroot/usr/ports     mounted   yes      -
zroot/usr/src       mounted   yes      -
zroot/var           mounted   no       -
zroot/var/audit     mounted   yes      -
zroot/var/crash     mounted   yes      -
zroot/var/log       mounted   yes      -
zroot/var/mail      mounted   yes      -
zroot/var/tmp       mounted   yes      -

Seems like /usr/local would be a handy mount point as well...

Also, i intend to use this box for jails and feel like all the 
filesystems below /zroot/var don't make much sense.  What layout are you 
using for as a jail host?

I'm thinking of blowing away all the mount points below var and just 
having one /var with noatime, noexec, nosuid, compression.  Bad idea?

Thanks in advance,

Rudy