Someone who holds back the truth, thinking they are keeping the peace, causes more trouble.
Before a society can be considered well-ordered, creative, and consonant with human dignity, it must be based on truth. Paul expressed this as follows —
So stop telling lies. Let us tell our neighbors the truth, for we are all parts of the same body. – Ephesians 4:25
And so will it be, if each person acknowledges sincerely their own rights and their own duties toward others.
Hard to think that the one who openly criticizes works for peace. Saying that, we can only think of the depression, fear, insecurity, chaos etc. caused by those who criticize because of their own issues with the same. It is not so much what you say as to how you say it. Criticizing to tear down is different from criticizing in truth with love. There are books out there to help one deflect criticism. If you are going to be critical to establish peace, do it in the spirit of love and peace.