I think that for most of us, it's very difficult to accept criticism. And even more difficult than accepting criticism is heeding it, i.e. making corrections in our lives as a result of it. The reason that's true, I think, is because criticism pricks our pride. The criticism we receive may be entirely true, but it's offensive, and that's because it points out our lack of perfection. And let's face it, we all want to be seen as perfect (well, at least more "perfect" than those around us).
We need to swallow our pride and to accept and respond to the criticism offered to us (even the "redeemable" parts of the nasty criticism that's hurled at us). We'll grow in our faith if we do, not to mention in our humility (and that's good because "God opposes the proud and gives grace to the humble"--James 4:6).
"Whoever heeds instruction is on the path of life, but he who rejects reproof leads others astray." (Prov. 10:17)