[jxy]

In some way, IBM APL2 [1] was trying to achieve that with all of their APs (associated processors, APL's own way to do IPC) and built-in workspaces. You can use APL as your login shell, since it really has all the things a normal shell/CLI provides and more. Mainframe APL had all the account management capabilities for people to login remotely through their phone lines, almost the same time as Unix systems start flourish.

Unix and later linux/BSD's took off largely based on their open source and easy to duplicate and deploy (c compiler everywhere), but APL had it's corporative baggage and remained a niche (very much like kdb+ wouldn't go open/libre, and IBM is still charging a fortune for APL2).

[1] http://www-01.ibm.com/software/awdtools/apl/apl2-v2.html