Why can't I use env variables in motd like $USER or `date` or $HOSTNAME?
If I do, it shows exactly what I type.

because that's the way it works.... it's just text, not a script.

/etc/issue would be out of a job.

I use /etc/profile and echo

Hee hee. But /etc/issue is used prior to getting logged in, motd after. No sense in telling the whole world that you've just upgraded all those software packages; make sure they're supposed to know about all those upgrades by making them go through the login process.

BTW, anyone know where 'issue" got that name? I've always used it to display the standard legal warnings before folks log in. Since "motd" is an acronym, wouldn't it be nice if they'd followed that convention when they came up with "issue". Perhaps something like: tcldwytrt ("The Company Legal Department Wants You To Read This") or maybe: aystbh ("Are You Supposed To Be Here?") I've actually put that one in "issue". At least until someone suggested that "Authorized Use Only" was more "professional" (but nobody pays attention to that phrase anymore; people actually noticed the one it replaced).

i've seen a number of places where motd is created per boot or per login, via the /etc/profile.d/ scripts. you can always add in a brand new script to the standard login that can do whatever you want