1) When Warren Buffett bought the Coca-Cola Stocks in 1987, it was because of the Duarable Competative Advantages, not because of the Coca-Cola's Management at that time.
2) During the Holding of Coca-Cola's Stocks, even though the Managements have been changed many times, some were good while some were not good, but Warren Buffett still hold it as far as it has had the Durable Compettative Advantages.
3) This is because Warren Buffett believes that Industry Change is much more imporatant than the Management itself.
4) This is the same as Charles Darwin who believes that lifes on earth can survive, it is not because they are the strongest and the most talent in the world, but it is because they can adapt themselves to the environmental change.