The coach won't get fired to get a new coach and turn things around (immediately), he'd get fired to appease the fans if they start tuning out in droves.
O'Brien's expiration date passed quite some time ago. IMHO, the only reason he's still here is he gives us the ability to tank without actually tanking. OTOH, if fans give up hope in the coach and start questioning players (unfairly), and follow that with major declining ticket sales and apathy then O'Brien is finished sooner rather than later. The team won't be able to afford to take these losses, even if the scoreboard losses mean a higher draft pick. TPTB will need fans to have SOME faith in the existing players and not turn on them.
Right now, O'Brien's 'coaching' is causing fans to lose too much faith and respect with existing players. That can't happen. Not to this degree.