Who they'll sue? The thousands of users and developers spread across all the world? or they will go after the Linux Foundation, Red Hat, Canonical, etc?
Remember that if one company goes down, another will pop up, and remember that Linux is a community project, so we can still continue to develop it in the open, with no companies, Linux started this way and it can survive this way, with the people working on it, as long as we can share code on the internet and there is interest.
Sure Linux has benefited a lot from companies and corporations, but I'm pretty damn sure that it'll survive on its own even if all companies die tomorrow. See LibreOffice vs OpenOffice.org for example, OpenOffice.org went through many companies and it's now gone, and LibreOffice is doing very well now. It could be the same with Linux, and if Nvidia decides to go after companies and sue them (because they are a leech), then Linux will still survive no matter what. I'm also not very sure what they will sue for, and I'm not sure their lawsuit will be very justificable, they will sue because they can't leech anymore?
Nvidia is going way too far with their stupidity, they won't survive this way.