What is criticism?
Is it good or is it bad?
Well it is both, criticism is both constructive and destructive depending on the context, depending on the idea being conveyed, and depending on the context.
Then why the sensitivity? Well it comes down to perception, here, people feel a certain way to a statement they might see as criticism, and then from there, takes it to where it wants it to go. Whether they want to improve on the flaw or not, it's entirely up to the individual. Obviously, there is a cause if the individual simply has an ego and goes through a denial, but most often then not, let's take it to a Utopian place where, people accept everything that they have is flaws then, we could say that it's very easy to accept the criticism .
But in reality more often than not, sometimes criticism is always going to be taken in the wrong way, because we tend not to accept flaws in ourselves.
So, for example, a criticism that was intended for something good, and to better someone else that was taken the wrong way, the other person would lash out. But then would it ever be the same for the other way round. That is a resounding no. Constructive criticism if dealt well, could benefit the person learn more, and do more to be better then they already were. It's not necessarily about perfection but it's more about improving yourself. Destructive criticism on the other hand is meant to destroy a person's self esteem but more often then not, it warrants a heavy lash out. But there are of course rare gems, who take destructive criticism and decide they want to make it constructive instead, and so, it also comes down to attitude, and how they take things.
Again I will say this though, a critique, is in itself an opinion and that's why, I posted this so close to the other one I just posted, so it is susceptible to interpretation and in-built mechanisms, that allow us to choose if this is something that will help us in the future or, something that will only stop our progress. It all comes down to choice and decision and the end result, is a consequence that will help us either way, because at the end of the day, we learn something.