I said interactive shell.

"Shell" is an ambiguous term

Bash can be

• the shell process parenting Perl
• the interactive CLI
• the language of shell scripts.sh

we mainly use Perl for the last part and full scale applications.

Taking into consideration that a big part of Perl's gene pool comes from sed, awk AND Bourne shell ( plus lisp), it's paradoxical not to use Perl as CLI.