Good Discussion and Argument could be very inspiring...
Positive persons could learn from words, instead of from own experiences or lessons...
Real friends are actually those who tell you the words that you won't hear from others, because they care you like themselves, and they know it's the help you need.
So let's welcome beneficial Discussions (it's different from criticism). :-)
When one considers it as criticism, the others learn, for the differences of the view or sides...