There’s been no love lost across the Taiwan Strait since the self-ruled island inaugurated Tsai Ing-wen as president last week, with China ratcheting up attacks against her out of concern she’ll make moves toward formal Taiwanese independence.

One Chinese official took it further Tuesday, tying Ms. Tsai’s political leanings to her status as a single woman. Without the burdens of love and attachments of family and children, Ms. Tsai developed a political style that tends “toward emotionalism, individualization and extremism,” according to Wang Weixing, a member of China’s Association for Relations across the Taiwan Straits, or ARATS, an organization that handles ties with Taiwan.

“When we deal with Tsai Ing-wen, we must always consider important factors like her experience, personality and psychological traits,” Mr. Wang wrote in a commentary carried on the website of the International Herald Leader, a newspaper owned by the government’s Xinhua News Agency.

Though the commentary landed amid a slew of official remarks, editorials and state media reports savaging Ms. Tsai, Mr. Wang’s remarks went too far for some in China. While other criticisms focused on Ms. Tsai’s reluctance thus far to endorse Beijing’s formula for continued political ties, Mr. Wang veered into what many readers perceived as misogynistic personal attacks, stirring a heated backlash on social media.

“This is very shocking. How did such dirty and obscene viewpoints get associated with Xinhua,” Gao Lidong, chief editor of a local news website in the southeastern city of Jiujiang, wrote on his verified Weibo microblog. Another Weibo user chimed in: “Looks like Xinhua wants to become the public enemy of the millions of unmarried women in China.”