Madison County and East Ridge were formidable teams back then. For example, Madison County was actually ranked #1 all classes(Beef O'Brady's poll) coming into the 2003 state title game, so losing to them by ten at that time was a "good" loss. In 2004, East Ridge was undefeated in the regular season and lost a close playoff game to state finalist Lake Gibson. ER came into that 2005 Columbia game as one of the top-ranked 6A teams in the state at the time, so Columbia losing to them by one point likely didn't hurt them much in the polls either.
The pollsters have had a love affair with Columbia for many years. Maybe there was some of that, "this has got to be their year" thinking, and it was difficult to let go of a strong preseason ranking when it started to appear that a Columbia team was not going to contend. I don't mean that as a knock on Columbia. I just cannot tell you how many times I've seen Columbia ranked highly in the polls, only to disappoint come season's end.