Serena Williams was fined $17,000 (£13,100) for the code violations that included calling the umpire a “liar” and “thief” in her US Open final loss.
Williams, beaten by Naomi Osaka, was docked a game for verbal abuse and had a point penalty for racquet smashing and a code violation for coaching.
She later said it was “sexist” to have been penalised a game.
“The umpire was following the rules by the book but Serena has a point.”
Barker, a former world number three and 1976 French Open champion, added that “tennis was the loser” from Saturday’s events.
Williams’ fine for the code violations, imposed by the United States Tennis Association (USTA), will be deducted from the $1.85 million the American won as the runner-up.
“I’ve sat courtside watching the men ranting at umpires and they haven’t been given a violation,” Barker said.
“The fact that it was to be a game violation then robbed the crowd of what potentially could’ve been a third set.”
Osaka, 20, won the match 6-2 6-4 to become the first Japanese Grand Slam champion.