At work, our performance must be flawless. The toll taken by criticism is immense. In an atmosphere of criticism, work team members become defensive, silent when it's time to express ideas and hesitant to take risks. A manager who lets no criticism go unspoken soon heads a group of sick and fearful people. Criticism is carping.
Criticism is acid to the souls of others.
It etches away at the worth of another person. If kept up long enough and hard enough, it will destroy a person, a relationship, a trust. Urge them to better performance. Inspire them with a vision. Document failures to meet expectations and discuss them objectively.