So often, the majority of the response is nothing but pure sarcasm from those who disagree with the author. By sarcasm, I mean: those nasty, wounding, irony tinged "comments" designed to bring pain, contempt, and ridicule to the victim. When poorly used, this form of "wit" is ... witless, cruel, and bullying.
I find it infuriating when the author whose work has just been lampooned is someone who has spent many years gathering the knowledge distilled in her/his article and the commenter puts forth no reason at all for her/his knee jerk fusillade of rage, reactionary name calling, and dismissive contempt ... and feels no need to apparently. Well, I'd better stop that before I descend into sarcasm myself. It's so very easy and popular in today's culture.
How to respond when sarcasm is leveled upon you? Keep a clear head. Do not take the bait and respond in kind. Seek a reasoned response from the user of sarcasm. Ask questions about why she/he feels the way he/she does. Insist on turning an impromptu comedy club routine designed to belittle you into a conversation. Gently and with actual humor try to tease out the points that might be found within the complaint and ask for an explanation of those points and some valid proof that supports them. It's hard, often incredibly so, but it might lead to a real conversation, one that could turn out to be worth having.
Well, my five minutes are up. Good luck!