I think it's just a matter of wording that might be causing a misunderstanding. I don't think he said that this is caused by women 'deciding' to walk away, but rather, for the first times in history, women as a whole have far more agency than they ever had in deciding to be in a relationship or not.

Take everything I say with a grain of salt because I'm not a man. I'm going to make a lot of assumptions about cis men here.

Under the patriarchal norms, many men are raised to derive their self worth based on things that are not always fully within their control such as wealth, looks, employment, etc, many of which are conflated with their ability to attract a partner. Some of these men may have also been socialized into believing that finding a sexual partner is a valid subsistute for emotional connection, because horniness and anger are the only acceptable emotions. This leads to the idea that all women exist to resolve their repressed mental health issues and sexual frustrations.

It's a confusing time for these men because not only are many women becoming more selective towards feminist men who don't adhere as strongly to these ideologies, but many women are also just happily single. Feminism has taught many women, but not enough men, how to live a fulfilling life beyond patriarchal norms. It hasn't done enough to teach men how to find self worth independent of women, how to embrace and process emotions, how to address mental health issues, how to recognize male sexual assault, how to live by yourself, how to empathize with peers, etc.

Women walking away from men is a symptom of feminism teaching them how to fulfilling lives as people, and we have yet to do so as effectively with men. It's not that feminism is teaching women to become single, but that a partner with antiquated views is no longer a prerequisite to a fulfilling life.