It's true. The problem with "New Coke," come to find out, was the legacy of original Coke. It was more than a drink. It was a landmark... an icon... an irreplaceable piece of Americana. When New Coke hit the market, consumers actually reported feeling betrayed even after they said they liked the taste of New Coke better.
Coke admittedly missed the entire emotional connection to their product. It wasn't about the drink. It was about they fierce loyalty consumers had to something they'd grown up with for generations.
In order to write effective copy, you have to understand your target audience. Coke thought they did. Nobody ever had the foresight to ask the question, "Will you have a cow if we discontinue original Coke?"