For big projects use a language like Perl.
There are a few things you can only do in bash (for example, alter the calling environment (when a script is sourced rather than run). Also, shell scripting is commonplace. It is worthwhile to learn the basics and learn your way around the available docs.
Plus there are times when knowing a shell well can save your bacon (on a fork-bombed system where you can't start any new processes, or if /usr/bin and or /usr/local/bin fail to mount).
