I'm not going to quote the entire article. You may find it useful to pull it up in a parallel window if you want to follow along.
In the first paragraph the author, Alison Rowart, "...confidently predict that come next August, when the 83rd World Science-Fiction Convention opens its doors in Glasgow, there will not be an anorak, a roll of tin foil or an anal probe to be had this side of the Cairngorms." I think that this is what first started thinking that this was an insult piece. I'll admit that as a speaker of "American" I'm not sure what an anorak is off the top of my head. However, the references to tin foil and anal probes remind me of the typical, and in my experience nearly 100% wrong, impression that SF fans are into UFOlogy, and thus more subject to paranoid tendencies.
My impression that this was what the author believed was increased in the next paragraph where she writes: "What the mad fools fail to appreciate is the risk involved in rolling out the red carpet to people who are, to a man -- and they are all men -- wired directly to Mars." Now, I admit that this sentence could be taken to imply that fen are forward, and spaceward, thinking; which I agree with and think is a compliment. But, in light of the first paragraph it didn't work that way.
Things start to get insulting again in the third paragraph, where she all but states that anyone who would dress in costumes based on their favorite book or TV show suffers from a mental illness. In this same paragraph she does let loose with the fact that she knows, or has at least researched, the middle name of James T. Kirk; perhaps the first sign that she actually has some fanish tendencies herself.
The next paragraph is a pretty accurate portrayal of many fen, if we ignore her complete lack of knowledge that fandom is now nearly 50% women. However, I didn't notice this on my first read, since I was still reeling from the earlier comments.
However, the next paragraph goes on to imply that fen do fannish stuff to escape from their personal unhappiness: "Those who dress up as Zogon the Warrior King from the planet Teflon do so because they want to stay in their own safe little worlds, not connect with others. Happiness is an enemy like the Daleks, easily defeated by the simple act of running upstairs, or a warm gun that has just zapped an unfriendly green critter."
Work is interrupting, so I have to cut this short. The rest of the article is, to be honest, fairly humorous. I'm not a professional writer, and would not even consider trying to write humor. But, I'm fairly sure that humor looses its effect on many when the writer starts out by playing up insulting and wrong stereotypes.