Tarana Burke, who founded the movement against sexual harassment and assault, said the former vice president’s light-hearted response was “disrespectful and inexcusable”.
Ms Burke, who first started using the phrase “MeToo” to raise awareness about the prevalence of sexual misconduct in 2006, said the women were right to speak out against the veteran Democrat.
But she said Mr Biden appeared to be misconstruing the point they were attempting to make.
“So now he’s making jokes? This is disrespectful and inexcusable,” she wrote on Twitter.
She added: “It’s not that people become more ‘sensitive’ over time as Biden suggested. And it’s not just about personal space or intention – it’s about bodily autonomy, it’s about power and leadership, and it’s about living into who we say we are and who we want to be.”
“He has *not* been accused of sexual assault. No one is calling for him to be incarcerated or sent away. He has been called to task for deeply problematic behaviour that many folks, particularly men, engage in regularly – and that’s a GOOD thing.”
Society could not only be angry when it is a “Weinstein situation”, Ms Burke said, referring to disgraced Hollywood producer Harvey Weinstein who has been accused by more than 80 women – including some of the most famous actors in Hollywood – of varying degrees of sexual misconduct going back decades.
He is currently facing criminal charges on five counts of sexual abuse, including rape, relating to two accusers – charges he denies.
Ms Burke said that “lesser talked about, often ignored violations and indignities” serve to intensify a “culture of silence around all sexual harassment and violence”.
Mr Biden did not directly address the accusations in his first public appearance since several women came forward with allegations of unwanted physical contact.
The 76-year-old, who is widely expected to enter the 2020 presidential race, was introduced by the president of the union, Lonnie Stephenson, as he took the stage in Washington at a gathering of the International Brotherhood of Electrical Workers on Friday.
“I just want you to know – I had permission to hug Lonnie,” Mr Biden quipped.
The crowd, which was largely male, burst into laughter. The politician later made a similar joke after inviting a group of children onstage and putting his arm around a young boy.
“By the way, he gave me permission to touch him,” he said, again sparking laughter.
Mr Biden said: “Everybody knows I like kids more than people”.
The politician, who has been jointly elected twice as the running mate of former president Barack Obama, has not been accused of sexual assault or harassment but the women have said they felt he violated their personal space.
Before his appearance Mr Biden, who is likely to be among Democratic favourites if he were to launch his third run for the White House, promised to change his behaviour in a video.
He said: “Social norms are changing. I understand that, and I’ve heard what these women are saying. Politics to me has always been about making connections, but I will be more mindful of personal space in the future. That’s my responsibility and I will meet it.”
Speaking to reporters after Friday’s event, Mr Biden was asked if he would apologise to the women directly.
He said: “I’m sorry I didn’t understand. I’m not sorry for any of my intentions.”
He added: “I literally think it is incumbent upon me and I think everybody else to make sure that if you embrace someone, if you touch someone, it’s with their consent, regardless of your intention.”
At least four women have recently come forward to accuse Mr Biden of unwanted physical contact.
Lucy Flores, a Democrat who served in the Nevada state assembly, former congressional aide Amy Lappos, Caitlyn Caruso and DJ Hill. All said he either touched them or hugged them in a way that made them uncomfortable.
Donald Trump, who was accused of sexual harassment or assault by two-dozen women when he ran in 2016, has capitalised on the allegations to mock Mr Biden and tweeted a doctored video showing Mr Biden appearing to put his hands on his own shoulders.
Pressed about whether he deemed Mr Biden a threat on Friday, the president replied: “No, I don’t see Joe Biden as a threat. No. I don’t see him as a threat. I think he’s only a threat to himself.”
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