1. The whole spy / compromising national security thing are as far as I know unproven.
2. Affairs by themselves, while not ethical, are fairly tame compare to other prominent tech figures like Musk.
If it comes out that he did indeed compromise national security knowingly, then that's a different matter of course.
Ezra Klein interviewed Jensen about 1.5 months ago and I had an off-putting feeling from it, and thought a lot of his answers were laughable. He sounded like he was obviously lying. A few days later, Klein interviewed Bill Gates and sort of anonymously brought up the arguments that Jensen made. You could see a visible disbelief of the arguments in Gates' face and posture, even saying "I almost can't believe you're asking that". (Not that Bill Gates is some paragon, but it wasn't close to a respectful disagreement.)
But one of the wealthiest people on the planet gets fired, suffering zero personal hardship as a result, and everybody's up in arms. How could you do this! They all do this, how dare you single him out!
I think that there's a pervasive idea, especially in the tech/startup space, that making money is a moral good. Not merely that making money is compatible with being a good person, but that it makes you a good person, and the more you make the more good you are. Firing an ultra-rich person is therefore basically an affront to a saint. Never mind that it doesn't put them under any hardship, that they and their heirs will still be wealthier than any of us can even conceive of. It's morally wrong to do anything bad to such a good person.