Well, I'll put it this way... if there is unfairness based on gender, the data says that it's not in favor of women. Since I'm still new I spend a lot of time looking at #introduceyourself and newly submitted posts finding hidden gems to follow, so I get a pretty broad taste of what's on this site, and the vast majority of it is written by men because of the 5-to-1 ratio. When you get to trending, there are even fewer female authors. This post was inspired by two recent trending articles that each made hundreds of dollars, and in each case the articles prominently featured complaints about how "hot girls" make so much money (ironically), with plenty of cheering on in the comments. So from what I see there is serious resentment against women among some very popular male authors here.
On the other hand, my feed looks very different because it's heavily curated to my tastes, and I know that we more or less run in the same crowd. I don't follow any men who make sexist comments about women, but I do follow many badass super talented women with excellent taste in resteems, as well as many badass super talented men. If the whole site looked like my feed, this would probably be the most awesomely not sexist social media platform on the whole entire internet. ;)