Do 6+ numbers really not matter as much as I am lead to believe?

Hopefully someone can help me understand something. In ratings discussions, it is repeated over and over again that 6+ numbers don't matter. However, I've never seen a station flip that was doing well 6+. However, using data David Eduardo posted in another thread, one of the CHR stations in my market, KBKS, has been stunting for a few days now, despite looking to be in the top 10 in billing, with the competing CHR, though much higher rated, still around the same in billing. There are also many stations that are lower than KBKS, which don't necisarily blow anyone away ratings-wise, but hold their own. These are all higher than KBKS though. In another example from Spokane, David also sent me numbers from 2011 and 2012, when KIXZ flipped from Country to CHR. In this case, billing was up slightly, not sure where ratings were 6+ before the flip, but were the lowest of the fm signals in the market after the flip. That slight uptick in billing was drastically offset by a loss in the top biller, KKZX. I don't have the billing numbers since, but I know that the station's fate didn't improve, even with a rebranding, so it went back to Country. It still had no luck so went Alternative, I don't think numbers for that are in yet. That being said, I understand that 6+ isn't, and shouldn't be, the only number to considder when making format adjustments, but how can anyone say they're completely meaningless when there's only been one example I can think of when a station that was higher rated than its competitor flipped? Even in that one example, nobody in the industry outside Entercom really saw that coming, as it was also higher billing than its competitor.

It depends on what you use them for. There are lots of other metrics to use. As others have said, you get what you pay for.