I definitely agree that we need a higher bar for moving something to
approved than just "we thought this was a good idea in the past." I feel
the same way about re-approving specs cycle-to-cycle, for what it's
worth.
Using the backlog directory is fine, but I don't really see any point in
doing that versus just leaving things as unmerged in Gerrit. I'm sure it
matters to someone, but merging something that meets the "sure, we can
put that in the backlog" bar at one point in time, which still needs to
be re-reviewed in order to put it in the "okay we will actually let this
in now" realm seems like not that useful of a dance to me.
I agree with Dan here. From a contributor's perspective what does having a spec in the backlog directory give me? The promise of a future conversation about approval? I have that in the form of a new review already.
Assuming it solves some not-obvious-to-me problem, as long as we retain
the re-review requirement then I guess I have no objection.
I think the problem the backlog directory solves is that it gives core a way to give a soft no that makes contributors less upset. I don't see a lot of value in that though. If the spec is a no then just say no. If its a big enough problem for the proposer they can hold their own patches or fork nova, much as people such as StarlingX, HP, and Rackspace Public Cloud did back in the day.
Michael