I did not find in the article what the problem is. It was angry because there were "so many men". But is that a reason to be angry?

The author says that she was offered less than before. But what does LinkedIn have to do with that?

The author says that her time off to take care of kids set her back. I have male colleagues who also were without work during the pandemic.

Also, I use LinkedIn to stay in touch with colleagues, globally. A large percent of them are women. In fact, during the pandemic I met quite a few new collaborators, and more than half of them are women - one in Boston, another in the Netherlands, and another in Zurich. I hope they don't all cancel their accounts!