It is offensive because it has high potential to create a hostile environment for women. This isn't just me and a few people making shit up, read my comment, it's obvious that the authors knew they were on shaky ground. They tried to defuse the situation with a cute little comment, but it would have been better to just change the name.
Read this comment for a better explanation if you're actually confused: https://news.ycombinator.com/item?id=7121717