It's worse than that. Much much much worse than plain greed. Supply of manufacturing capacity for this kind of hardware is severely limited. TSMC can't produce enough to meet all that demand. NVIDIA not selling 7.5B worth of chips to China does not mean they would lose the 7.5B worth of chips. They could have sold them to American companies, which are all in a frenzy to build datacenters.
No, this is just a classic case of treachery. Jensen Huang, whether bought, blackmailed or because of tribalism, has decided to support China. In an interview, he was getting very angsty when someone asked him why sell chips to China, and said "victimizing them, turning them into an enemy, likely isn't the best answer":
https://youtu.be/Hrbq66XqtCo?t=3517
People refuse to believe it when it's a billionaire, but they too can be very tribal, even if they lived most of their life in the so called melting pot of the United States of America.