Open eyes,you highlighted the differences between criticism,and constructive criticism.On the one side ...one may object to a thing stating it is wrong...nothing more....perhaps the receiver is left shamed.On the other hand,making a point to say that something changed would benefit the person; and the outcome if approached differently would assist them,....is a criticism of support.If you find something with fault,add an alternative.Leave the focus on the action ...rather than the person.