From the CBS article:
No matter how you think professional athletes should behave, Williams is right to be angry. Male players are often excused — celebrated, even — for putting their emotions on display in the heat of the moment. In fact, Ramos — the very same umpire who penalized Williams a game for calling him a "thief" and accusing him of lying — has tolerated similar, and arguably worse, outbursts from male players on numerous occasions.
At the 2016 French Open, Australian player Nick Kyrgios blew up at Ramos after he was given a warning for raising his voice at a ballboy. "That's bulls**t. Are you kidding?" Kyrgios shouted at the official. "Bulls**t, f***ing bulls**t." He was given neither a point penalty, nor a game penalty.
At the 2017 French Open, former world No. 1 Rafael Nadal threatened Ramos, "Give me the warnings you can, because you will not referee me anymore," he said. Nadal referenced his comments in a post-match press conference. No penalties were given.
While I find many of the arguments made here so far compelling, I find the above compelling as well. Which is why I remain undecided.