Didn't read the article, but my two cents: wear clothing that you look good in, and is suited to the occasion.
Sorry, but I look good in jeans and will keep wearing them in appropriate settings.
I'm in the 'no jeans' brigade. I would be much more comfortable in some well-worn moleskins or cords in this scenario. But this is very much for me - I'm not in the 'no jeans for anyone' camp.
what about sports activities ?