This is 100% right. I've only worked in a bar and a restaurant for a combined total of a year and I've heard so many women repeat very similar comments as to what offended her on a daily basis. Bad jokes about tits, pussys, and small dicks. Some people are aggressive, plain and simple.
I've also worked with several women in tech who very strongly resisted the feminist movement and felt they needed to carve their own path. They are some of the most badass software developers I've ever worked with and without them their teams would falter into a horrible mess of terrible code and documentation. If anything I'm understating how important they are to the companies they work for.
It's my personal belief that the changes with women's rights in our country over the several decades has been one of the best things to ever happen. For the majority of my life growing up it has been just me and my mom, and even in the past two decades I've seen a lot of really good change. I can't imagine the amount of change in the past four decades.
The issue is that much like the BLM movement SOME people, not all, are turning it into an us versus them situation. This mentality is never productive and indefensible. Read the final statement "We won’t let them grind us down."
Right now my Facebook is jam packed full of friends posting about how everyone needs to revolt against white men because of the transsexual military ban that Trump just enacted. I'd love to have a discussion with them about how Trump's actions don't represent white males everywhere, but they will turn hostile and rip me to shreds the moment I say anything which opposes that statement. They've done it before and I don't want to argue with my friends like that.
All of this said, the manager is horribly sexist with comments like below. Even if that is true, there is a strong context in the situation. Why even bring it up, what point is he trying to make?
"Later that night, he also said that women had a smaller brain. That’s when I couldn’t take it anymore and left."
That's really fucked up, go finish the contract and find a better team to work with. Life is too short for shit like that. And please don't turn this into us versus them. Find better people to work with.
EDIT: In the comment section responding to someone suggesting a company for her to work at, she wrote:
"Thank you for the tip ! I have to keep fighting but it’s not easy, I know that 42 school is very sexist as well and there are only 7% of women there so I’m not so delighted to go there. But that school is very famous in France and I want to acquire those low level C language skills."
Then don't go! Go work at some place where people treat you with respect.