This is primarily for replacing people that die or become incapacitated in office. Keep in mind, the only time this comes into play is when someone voluntarily steps down or simply vanishes (stops attending meetings or getting approval pre-meeting to be absent). Allowing this prevents us from having an entirely vacant board.

Imagine the situation we had not long ago on Council. We elected members, and one by one they stopped being there until only one was left. What it that happened to the Board? What if that single person got hit by a bus? Allowing replacement (preferably from the list of candidates from the last election cycle) avoids that.