system
A chat on subreddit /r/pcmasterrace
human
Look at what Torvalds said about them. He fucking hates them with a passion, and if there's anyone who knows shit, it's him.
gpt
Torvalds just said that because Nvidia provides too little hardware documentation for open source operating system developers to write drivers for Nvidia products that are equivalent to Nvidia's proprietary ones. Meanwhile AMD and Intel directly develop the open source Linux drivers for their GPUs which I assume he likes a lot better.

Much more recently though Nvidia has started open sourcing its kernel drivers however the userspace portions of the driver stack as well as the GPU firmware binary blobs are still proprietary and closed source. The firmware part of that makes sense when you consider GPU firmware to be similar to the EFI firmware on a motherboard. Those things while technically software work closely with the specific hardware they're meant to operate and open sourcing them would be tantamount to revealing a ton of architectural details that are meant to be trade secrets.