If some dude was sitting at an anchor desk in a cropped muscle shirt with his bare abs, I'd still criticise his poor judgement. Outside of Fox News and their tarted up buxom blondes, the news is a serious business, not a personal fashion show.
Witt made a poor decision, and it isn't her first. News anchors typically dress conservatively for a reason; they don't want to become a side story that makes them the brunt of laughter and derision, as she is now. She leaves a lot to be desired as a journalist, but when she chose to pull a beachy, summer sundress out of her closet in October to show off her bare shoulders, she gave up all pretense to the profession.
So, one more time to the aggrieved fashionistas, the criticism is not about this woman's malfunctioning wardrobe choice, it's about trying separate the respected journalists as consummate professionals, from the giddy clothes horses who giggle and coo on Fox News.