Shouldn't a company in a country with these[1] practices rightfully be met with distrust in these contexts? Spoiler alert: I'm not a culture (or politics) relativist.

[1] https://en.wikipedia.org/wiki/Internet_censorship_in_China

It seems a little weird that you'd trust a web browser developed by a company that resides in a country famous for massive, systemic internet censorship, as well as habitual government interference in and control over domestic companies' operations.

That doesn't mean that today's Opera is definitely an untrustworthy piece of software, but it does raise the probability quite a bit.

I'm saying that the Opera browser is beyond rescue because it's now day-to-day controlled from Beijing.

I can only assume that he is implying that any involvement of/by Chinese people is a very bad thing per se.

Not by Chinese people, by the CCP. Which it becomes as effect of being controlled by a legal entity in PRC. This has nothing to do with ethnicity or culture and everything to do with the current political situation in China.