One morning years ago, I was driving to work, listening to the car radio. The retiring head of Coca-Cola was being interviewed. His main claim to fame was that he was responsible for the introduction of 'New Coke', one of the most costly marketing failures in history.
He explained that as the head of a famous company, he received hundreds of unsolicited letters each day. He had instructed his secretary that although mass mailings were to be discarded, she should deliver him every day a representative sample of the letters he received from real people. She obviously took him at his word, because one day he read a letter asking him to sign and return it (SAE included) "because the signature of the CEO dumb enough to change the flavor of Coke has to be worth good money someday". He laughed and signed the letter.
He started thinking about the state of mind of the person who sent this letter, knowing that there must have been many similar letters for one to have got through. Why were people so loyal to the existing drink that they would be so angry at a change. As he said over the radio "I don't know why it hadn't occurred to me before, but I suddenly realized that people bought a particular brand of Cola for the same reasons women buy a particular brand of perfume, not the reason they buy a particular brand of bread. We should be hiring our marketing managers from perfume companies, not food companies."
He called in the VP of marketing, and discussed his insight. The VP reluctantly agreed that there was considerable truth in the idea, and agreed to pursue it. It took much time and effort to overcome the obstacles. For example, perfume companies pay marketing people more than food companies, so hiring them away would require high offers, thus making the existing marketing people jealous. Eventually these obstacles were overcome, and the perfume marketers were very successful. The CEO claimed that Coke had increased its market share over the next few years several times more than it had lost in the New Coke debacle.
The CEO ended the radio interview by saying "if the man who sent me the letter is listening, I want to say 'Thank you. I hope you sold the letter for a good sum, because the insight you gave me helped to raise the value of my stock options'".
Now I realize that the CEO had probably massaged that story to make himself look wiser than reality, but that doesn't affect the moral of the story. Whenever you are criticized, the message probably contains useful information, as well as being uncomfortable. If you can control your reaction to the discomfort, you can benefit from the information. The fact that the person criticizing you is stupid and irrational does not mean that his communication lacks value.