Notice two things that the 49er's and the Ravens did this season. They made changes in the middle of the season when they saw something was not working.
Kapernick was put in for Alex Smith for the 49er's
Cam Cameron was fired and Caldwell took over of the offense for the Ravens.
Key point is that they evaluated the talent and made the necessary move. Yes it could have gone either way, but unless you take a chance and believe in your football people you settle for good instead of great.