I strong disagree with that statement. I can write a shell script to find all the .c files in a directory and it's subdirectories and add a subversion keyword to it in a for-loop that I write in one line in Bash. I doubt doing the same in Perl would be as quick.
But Perl, Ruby, Python as certainly great for more complex tasks. But beware that if you use any external modules not distributed as part of the core of the Linux distro your organization uses, you need to first ensure that those modules have been made available on each system you would use this script, thus adding another complexity.