Honestly, Jessica's costume was never even singled out. Fans complained about Carol's costume because she was being drawn by Greg Horn all the time so she was just turning into a cheesecake character.
Jessica didn't get the same treatment, and I literally never saw anyone say Jessica's costume was bad or sexist. (Although a couple didn't like the crotch triangle which is dumb because Spidey has that, too.)
The real reason that they changed her costume is because they wanted to relaunch her solo with a Hawkeye approach. That was their formula in 2013-2015, and they wanted to veer even closer to it for Jessica (maybe because of the Kot/Walsh Secret Avengers book with the similar tone?). If you look at all of Kris Anka's preliminary designs, he was pushing to have something closer to a full mask, which Marvel shot down, which I think is probably because they wanted it to feel more like Hawkeye (casual costume, no mask, street-level and personal problems).http://www.tencentticker.com/projectrooftop/2014/12/19/new-spider-woman-by-kris-anka/
That take on the costume is better though, and I wish Marvel would take a look at it. Her current costume just doesn't really work outside of Javier Rodriguez's style