16. Mike Singletary
Singletary may be the single most disastrous 49ers coach ever. They fired Mike Nolan and promoted Singletary to the top job. He went 5-4 in his first year and appeared to stabilize the franchise after a rough year. However, it went downhill from that. They missed out on the postseason in his second year. Then Singletary started 0-5 in 2010 before they fired him.

One of Singletary’s main problems was his lack of composure. He became emotional in front of the media and went on excessive rants. Singletary was an excellent linebacker’s coach but couldn’t handle the pressure of being in charge. The team didn’t like him because of his overbearing manner. He infamously dropped his pants in the locker room at halftime (via NBC Sports).