I used to welcome opposing views for the simple reason that I whatever beliefs or values I hold, I am probably somewhat biased towards them, and critical input is therefore something extremely valuable to me.
However, more and more, the opposing views are of the type described by the author above. People are less interested in actually broadening their horizon, in finding synthesis between thesis and antithesis. More and more, it's just about finding a position, digging in, and attacking the other with full force.