Apart from the reasons CrLf was pointing out, here is another one: The shell (and a set of utilities) is standardized - it's part of the POSIX standard - this is important for some organizations. If you program in the subset of bash that conforms to the standard (enforcable with bash --posix) you are programming against an interface that will likely be more stable over the coming years than Python or Perl (think Python 2->3, or the long awaited Perl 6).
As always, it's a tradeoff, i.e. the best solution depends on the problem and requirements. Many problems shouldn't be tackled with the shell, for sure...
Standard Shell Command Language: http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_...
As always, it's a tradeoff, i.e. the best solution depends on the problem and requirements. Many problems shouldn't be tackled with the shell, for sure...