Since when did pointing out egregiously malformed reasoning, destructive personal attacks and factually incorrect assertions become a “slamfest of others[sic] opinions”? Empirically, some positions are simply wrong, opinions notwithstanding. If people choose to champion these unsupportable positions, they don’t get to complain when people point it out.
Ann Coulter is a fringe political pundit who often makes up for a lack of substance by simply attacking people and their countervailing opinions. The cost of this is that she is far more likely to muddy a discussion than clarify it. Getting to a true answer or a workable policy is already a challenge; why should we indulge someone who makes this even harder?