Martina has spoken:
https://www.nytimes.com/2018/09/10/opinion/martina-navratilova-serena-williams-us-open.html
Martina, like Serena, also describes herself as "human rights activist". But as opposed to Serena, she is actually a good role model in her activism. She understands the difference between a childish outburst and a true issue of gender inequity in tennis (and life in general) because she has been campaigning for said issue. Let's quote Martina from above:
I don’t believe it’s a good idea to apply a standard of “If men can get away with it, women should be able to, too.” Rather, I think the question we have to ask ourselves is this: What is the right way to behave to honor our sport and to respect our opponents? - Martina Navratilova
And another quote:
It’s difficult to know, and debatable, whether Ms. Williams could have gotten away with calling the umpire a thief if she were a male player.
But to focus on that, I think, is missing the point. If, in fact, the guys are treated with a different measuring stick for the same transgressions,
this needs to be thoroughly examined and must be fixed. But we cannot measure ourselves by what we think we should also be able to get away with. In fact, this is the sort of behavior that no one should be engaging in on the court. - Martina Navratilova (my emphasis)
I can only add to it: Martina is my hero if it comes to women's rights (and I really am a big supporter of women's rights, the fact that I am a man notwithstanding) while Serena is a big shame. It just makes me cringe when Serena is absurdly trying to generalise her petulant problems on the court to gender inequality issues. And worst of all, some of her fans are deceived into said generalisation.
(sic in all my quotes, as they are in American English)
For the record, I am a big Serena's fan and really wished her to win it and equal then surpass Court's record. And I feel doubly disappointed that she didn't do it and in such a shameful style.