The Jargon File (version 4.4.7, 29 Dec 2003):

brain-dead
 adj.

    [common] Brain-damaged in the extreme. It tends to imply terminal design
    failure rather than malfunction or simple stupidity. ?This comm program
    doesn't know how to send a break ? how brain-dead!?


The Free On-line Dictionary of Computing (30 December 2018):

brain-dead

   Brain-damaged in the extreme.  It tends to imply terminal
   design failure rather than malfunction or simple stupidity.