Earlier quoted context omitted.
geohot wrote tinygrad. This is not about believing his skills to translate to other domains. It is his domain. You definitely shouldn't trust what geohot says about infinitary mathematics or (god forbids) quantum mechanics. On the other hand, you generally should trust what he says about machine learning software stack.
Tinygrad isn't a big selling point. I'd expect most people to be able to build something similar after watching Karpathy's micrograd tutorial. Tinygrad doesn't mean expertise in ML and it similarly doesn't mean expertise in accelerator programming. I wouldn't expect a front end developer to understand Template Metaprogramming and I wouldn't expect an engineer who programs acoustic simulations to be good at front end.…
If you haven't worked with someone who's smarter and more motivated than you are, then I can see how you'd draw that conclusion, but if you have, then you'd know that there are full stack developers out there who do both better than you. It's humbling to code in their repos. I've never worked with geohot so I don't know if he is such a person, but they're out there.