The case for the /usr merge

however since package managers don't know how to deal with a /usr that's shared between machines (an update isn't confined to only making changes within /usr) I really question the value of this argument as a practical matter.

I tend to build my machines using /, /var, and a spare / (for upgrades rollback) but that doesn't mean that all files that are in subdirectories should get moved up.

it seems like a lot of this is to work around problems in the rpm packaging system, and that the arguments against it are dismissed because 'fedora is broken in that situation anyway'