It's not about their Chineseness. They're notorious, unapologetic GPL violators with a poor track record when it comes to privacy and general integrity (paying for reviews, etc)..
See:
- https://www.mozillafoundation.org/en/privacynotincluded/onyx...
- https://www.reddit.com/r/ereader/comments/13e8bw3/psa_onyxbo...
- https://news.ycombinator.com/item?id=23735962
- https://news.ycombinator.com/item?id=31247982
- https://news.ycombinator.com/item?id=37665408
- https://www.reddit.com/media?url=https%3A%2F%2Fi.redd.it%2F0...
etc...