This myth however was inverted by people pushing for /usr merge on various media platforms at the time. A common example of "what's wrong with split /usr" that

This myth however was inverted by people pushing for /usr merge on various media platforms at the time. A common example of "what's wrong with split /usr" that was pushed was things like dropping pci.ids database in /usr/share and it being required by code mounting /usr, and that mounting / and /usr separately in initrd was a wasteful complexity. In fact, today is the first time I have heard of reasoning that supported /usr on separate partition and I thought it was just an inversion done later by people who noticed possible benefits for some extra initrd complexity (btw, dracut and systemd oriented initrd scripts are stupidly complex. Including generating systemd units by text templating in udev rules as part of dracut boot process. Wtf)