I agree actually that Nvidia's strategic motivation here is their long-term position w.r.t. Intel and AMD, maybe even Apple/Huawei/Samsung. And that's actually a good reason for this investment!
I likewise don't think destroying the ARM ecosystem is Nvidia's primary objective here - far from it. It might not even be a secondary objective. But I do think the ARM ecosystem will be slowly torn apart either as an innocent bystander or as a less prominent secondary objective (given real-world complexities, probably some combination of both). When Nvidia buys ARM, and they explicitly buy them to improve their competitive position, there's only one direction where I see the incentives going. Those will be against the open ARM ecosystem, which is a breeding ground for big and small competition against Nvidia.
Even if Nvidia's primary motives are relatively benign, I think they'll inevitably create a sitation where the ARM ecosystem can't continue existing in its current form. That's where the real tragedy will be.
