

I think the common ground is a fear of loss of authority to which they feel entitled. They learned the “old” ways of SysV RC, X11, etc. etc. and that is their domain of expertise, in which they fear being surpassed or obsoleted. From there, it’s easy to combine that fear with the fears stoked by adjacent white/male supremacist identity politics and queerphobia, plus the resentment already present from stupid baby slapfights like vi vs emacs or systemd vs everything else, and generate a new asshole identity in which they feel temporarily secure. Fear of loss of status drives all of this.
Leaded gasoline had a lot of utility for a long time too. Even still has its niches in general aviation.