The priority of the GNU project has always been to free users, not to develop the GNU system. Since we have a free system, our priorities are to work on furthering the goal of freedom for all computer users.
Right now one of the biggest struggles in front of us is non-free Javascript, see https://fsf.org/campaigns/freejs and how companies are trying to cripple computers for everyone with "Restricted Boot", see http://www.fsf.org/campaigns/campaigns/secure-boot-vs-restricted-boot. Putting explicit effort on release "the" GNU system would not help any of those goals, hence why work and thought on the GNU system is not a current priority. Maybe when all software users are free from the shackles of software hoarders we can finish this, but until that day there are more pressing issues. The first version of the Hurd was release in 96, so just in the middle of the early and late 90s
