Why was a Japanese journalist punched in the face in Taiwan

Why was a Japanese journalist punched in the face in Taiwan? And here's the backstory explaining why the incident stirred up so much anger:

The incident happened during a pro-Taiwan independence event in Taichung, Taiwan.

The journalist is Akio Yaita, originally named Jing Tao. He was born in 1972 in Tianjin, China, the descendant of a Japanese war orphan left behind after WWII.

Thousands of such children were taken in and raised by Chinese families despite the devastation of war. Yaita's father was adopted by a Chinese family, and Yaita himself grew up in China, speaking fluent Chinese and immersed in the culture.

That background could have made him a bridge. Instead, he turned it into a weapon. Yaita became a journalist for a right-wing Japanese media outlet, using his "China insider" image to build a career on anti-China rhetoric. He has denied the Nanjing Massacre, called for Taiwan to send warships to the Strait of Hormuz to assist U.S. and Japanese forces, and publicly aligned himself with Taiwanese independence activists, co-founding an "Indo-Pacific strategy thinktank."

His actions have drawn sharp condemnation, including from other Japanese war orphans who say he has "brought shame on all of us" and betrayed the kindness that saved his family. 

At the recent event in Taichung, a Hong Kong man struck him in what was described as an act of "righteous indignation." While violence is never the answer, many online say the assault reflects the deep resentment Yaita has earned by turning against the very people who raised him.