I am a female (untenured) professor in the social sciences. I didn't find the post mocking. In fact, it is quite true. As a younger professor, I have been grappling with the issue of how to dress since I started this job. I consider myself stylish (but not trendy), and think that people should dress appropriately for work. Unfortunately, I don't have many older female colleagues to look to for inspiration. Most of my colleagues (male and female) seem to take no care in how they dress, coming to work in super casual clothes (often ill-fitting and sometimes stained or ripped!) that seem to convey the message that they either don't know how to dress well, or just don't care.
I have had colleagues comment on the fact that I dress up for work, which I have a hard time interpreting. I don't know if they are impressed with the fact that I take some care in my appearance, or are mocking it. I would describe my work wardrobe as business-casual, though more on the business side. I wear trousers or pencil skirts with blouses and cardigans, or dresses. I do not wear jeans (except some denim trouser pants I wear in the summer when not teaching). I seldom wear suits, unless I am at a conference or making an important presentation. I usually shop at places like Banana Republic, J Crew, and Ann Taylor. My clothes are modest, and usually on the more conservative side. I would prefer to dress a bit more "avant garde" and even to dress up more, but the fact that my colleagues are so underdressed, and that I am in a college town in the midwest, would make me look woefully out of place. I am actually bored with my wardrobe, but don't know how to make it more reflective of my personality without looking too dressed up for where I live and work.
I do think there are some older academics who look down on those of us who take fashion seriously. They seem to think that spending time on one's appearance takes away time from working on serious academic pursuits. I think the solution is for those of us in academia who do care about appearances to show them that one can be successful in one's career AND look good. The more of us there are who are successful and fashionable, the faster we can get out of this fashion rut in academia.
On a side note: Stacy and Clinton always say to dress for the job you want, not the one you have. That advice doesn't work for academics! Dressing like a tenured professor would make me look worse!