The article is kind of stupid, but accurately reflects how some people think /feel/act about cycling. One part of me wants to say, great, they are riding and saving gas, but the other part wants to scream, "get a helmet." But, you can't argue with people like that. I have tried.
I'm not embarrassed to say that I love fashion. But, even when I do errands on my Jamis, I wear cycling clothes. I've acquired a "casual" cycling wardrobe that looks different than my spandex (even though most pieces have some lycra or spandex in them) for this type of riding. I just cannot ride in my regular clothes. Like others said, I sweat, no matter what, even toodling along at 10-12 mph. And, like Zen, I get treated much more nicely by motorists when I am on the flat bar bike, dressed slightly differently. I love some of the "fashion oriented" cycling clothes that TE carries, although I don't have a lot of them, I would wear most of that stuff in "regular" situations. I guess my clothes buying habit has been mostly supplanted by buying athletic type clothing. I haven't tried riding in a skirt recently, though. My skirts are short, which would not work.
I have hazy memories of riding my 10 speed UniVega to summer school classes at ASU, in a sundress, with a Sparky backpack, in 112 degree sunshine. No helmet, of course.