Its not always because member dont want to change.It happens pretty often that opposite team has better players and suddenly few disconnects from that team so instead of switching,what end up resulting most best players stacked to one side,il wait for autobalance to take latest player,who joined.In that time il stay on spawn so advantage wont be that huge at this moment.This method is the best if you judge yourself better skilled then average and/or the latest person who joined.