Even Perl... It's not in POSIX (I'm fairly sure) and I can't imagine there is some critical utility written in Perl that can't be rewritten in Python or something else (and probably already has been).

As much as I like Java, Java is also not critical for OS utilities. Bash shouldn't be, per se, but a lot of scripts are actually Bash scripts, not POSIX shell scripts and there usually isn't much appetite for rewriting them.