I worked at Opera for a long time before it went Chinese, most of the time with Jon as CEO.
Best as I can tell: Jon von Tetzchner always had one primary goal - to become an industry titan, primarily like Bill Gates.
He founded Vivaldi after he was was thrown out by Opera's board in 2010.
I don't have any insight into why that happened, but I do know that at that time he was a terrible leader who simply wasn't able to prioritize and scope at all. Exactly anything that was "good" had the highest priority.
For the sake of his employees at Vivaldi, I really do hope that he has gone through some personal developments since then.
He did have a bunch of positive traits too! Can't tell in detail without exposing myself though.