|Gender difference? People must be sexist.|
However, I believe this lack of comments was not because of sexism; I think it was caused by the following facts.
1. Most suits look very similar, especially when you're ~10 feet away, and especially when you're seeing it through your TV screen, so would anyone really notice if he had changed suits? It would have looked very similar anyway.
2. Adding to 1: people fully expect newsmen to wear some kind of dark suit every day, because that's basically the only formal wear for men. So why would anyone notice this man's lack of variety? If anything, the audience expects him to wear the same suit every day.
3. He changed his tie regularly. This is important not only because the tie is usually the most unique part of a suit, but also because it distracts the audience from the rest of his outfit. These kinds of distractions can make a person miss some very obvious things. (see the first video link below). This experiment would have been more significant if he had worn the same bright tie every day.
4. The human mind is surprisingly bad at distinguishing little details from one moment to the next (see the second video link below); usually our brains just remember the gist of what we saw, such as "a dark suit".
Additionally, smaller details (like changing from one dark suit jacket to another dark suit jacket) are less likely to be noticed, and, following point 2, are less likely to be cared about even if noticed.
These videos were produced by Daniel Simons, a psychology professor at the University of Illinois at Urbana-Champaign.
These facts explain the results of the year-long suit experiment better than sexism, but the fact that so many people believe their knee-jerk reactions is concerning to me.