I just finished my second year as a university CS student, so my "real-world" knowledge is lacking.  I learned Java my first year, continued with Java and picked up C and simple Bash 
scripting my second.  This summer I'm trying to learn Perl (God help me).  I've dabbled with Python a bit in the past.
My question is, now that we have very readable, very writable scripting languages like Python, Ruby, Perl, etc, why does anyone write Bash scripts?  Is there something I'm missing?  I know my linux box has perl and python.  Are they not ubiquitous enough?  Is there really something
that's easier to do in Bash than in some other hll?
Apart from what others have said, I'd like to point out what's in my opinion the main reason to learn Bash: it's the (almost) standard Linux shell.
Other scripting languages are surely useful, and maybe a lot more powerful, but what you'll be dealing with when you have a terminal in front of you is... Bash.
Being able to manage I/O, pipes and processes, assing and use variables, and do at least some loop and condition evaluation is a must, if you want to manage a Linux system.
Is there any use for Bash scripting anymore?