How to silence the critics?
Offer them ways and request their suggestions for ways we can work together to solve the problem. Your critic is interested in criticizing more than they are in contributing something constructive. Their criticisms may be fueled by an implicit bias, unconscious act of discrimination or contempt or a propensity to respond with an adversarial tone. But the path to peace begins with communication.
Simply speak with sincerity to the problem, but ask, illustrate and/or suggest ways we can work to solve the issue, beginning with consideration for the problem above the individual. The person who is a critics will have little or nothing to say, the person who may have criticisms will respond back with sincerity.
Some people only want to be heard or seen. They need your argument to validate their misconceptions, bias, misunderstanding or point-of-view. They may be right, but usually someone who is right offers their criticisms uncritically, but considerately. It’s difficult to criticism consideration and unity without revealing your true intentions and motivations.
Remember that you don’t have to be wrong for me to be right.