No, they are the jerks. And they're often not qualified to perform an interview. No training, they don't know what they're doing most of the time. Probably the biggest problem here is the people performing the interviews are not qualified to do the interview. I received formal training on performing interviews and it still took 50+ of them until I did it well. Most of these people aren't taking it as seriously as they should be -- because they're jerks, probably.
Over time, the number one qualifier to accept an offer or make one is that I don't want to work with jerks. Neither do you. Good for you.
You're lucky to see such "flags" early in the process. So you're doing a great job finding out which jerky companies you won't like working for.
About what to wear: when invited for on-site interview, ask whether you should wear formal or informal business attire, always ask, its a perfectly valid question.
Anyone who says you are only there to be interviewed to fulfill some kind of gender quota is not someone you want to work for anyway. You want to be hired for the merit of your domain expertise and qualifications. I can't imagine any worse feeling than showing up for work every day and knowing that you're just the "token girl coder".
And you absolutely deserve feedback.
You'll be on the other side someday interviewing candidates, so please remember all of these experiences and make it a pleasant one for your next team members.
My best advice is that you have plenty of control. You can walk out at any time. You have the skills they need. It is your time. They need you.
Best wishes!