This is interesting. GNU inherits a lot from ITS, DDT and Emacs openness, where they had no security at all and you could edit the files from the whole system and import processes locally and over the network.The security there was to behave like a lady/gentelman and help/get helped. Also, crackers weren't interested as everyone could see everything users where doing at any moment. Data security? Restoring from tapes.

By setting up an open system on top of a permissions bound system (Unix) having limitations as an user looks really weird and with full of rough edges everywhere, with limited permissions even to mount a hard disk image. Namespaces in Hurd (+ maybe guix) solve that by giving the user lots of freedom to install and share whatever it wants without breaking a system.

That would explain why it never seemed to move forward.

TBF, that makes it quite explicit that the problem of Hurd never getting ready was due to the project governance (as in "this is not a goal"). A project that uses Mach could never get big.