24-hour BART service is a literal pipe dream. Without a second Transbay Tube, single-track overnight service is out of the question.
But the transit agency knows we don't give a damn for their stuffy explanations. Who cares that "Safety-sensitive, essential and/or California Public Utilities Commission mandated maintenance work can only take place when the trains are not running." Give it a rest, guys.
Tell us it's because there are ghosts in the tunnels at night, or at least make a Youtube video. You know, entertain us! Oh you did? Thanks!
Meh, needs more ghosts.