> It's not just the FOSS community, look at how non technical people react every time gmail, outlook or excel makes a tiny change to the UI (not to mention big ones). It really makes people angry when things don't work the same anymore, let alone when it doesn't even work anymore for their use case.

Like you note, this isn't a problem unique to Linux/"free Unixy OSes". In some ways Linux is actually worse than others, consider Gnome/Gtk Updates for example. Or how things like having a library to read a particular image format are quite normal around here; except that library has like half a dozen incompatible but actively used versions and around 1000 released versions. The Linux environment is very volatile and everything constantly changes and breaks. Modern applications bitrot exceptionally fast in Linux, while the community points to "but look this Xchess binary from 1992 still works". That's neat but covers few real use cases. The same community is then bewildered that both people and enterprises opt for distributions which move at a glacial pace and only releases updated software once every five years or so.