Did you miss the part in post #17 where mohtashims says that this wondrous code is going into all of the files in everyone's login directory where the filename contains profile or rc . So, these bash isms aren't just being run by bash and ksh users, they are also going to be run by original Bourne sh , csh , and tcsh users and will probably cause error messages every time advanced vi / vim users start an editing session, advanced mail users login or open their mailbox, etc. 
Oh, well...