Yes, I think you're right. In that case, it certainly wasn't the case back when Linux started. Intel and Redhat are the biggest contributors according to the Linux Kernel Development Report from 2017:
Intel 10,833 13.1%
none 6,819 8.2%
Red Hat 5,965 7.2%
So, "none", although it's the second biggest category, only accounts for 8.2% of contributions.