alt Hacker NewsLinux development is paid for either directly or in-kind by companies including Red Hat, IBM, Canonical, Oracle, and others. It's free to use and mostly open source but if it existed only on passion it would be something far less than it actually is.
People need to eat and have a roof over their heads.
Those companies pay the improvements they want for their usage case, which is usually far removed from what normal users want. I don't really need support for thousands of CPUs and terabytes of RAM.