I think we as a community should not stand in the way of a good question. If that means being a bit lax about chameleon questions, then so be it. I still would prefer that the existing questions are improved in the sense they were originally meant, but I can understand that that is not always possible. The only requirement I would strictly enforce is that they may not have any answers.
That all being said, normal criteria for good apply. In general, a question like this will always have a hard time. Usually they come from a negative score, with comments that don't make sense any more. I don't see that the example question is good.
I've had discussions with one user about a similar issue. You can find my answer here: May I convert one of my ill-received, deleted questions to a completely new one in order to try to work towards lifting my question ban?
There is nothing to be done. A mediocre or lower question that is closed will go the usual way of closed mediocre questions.
Comparatively decent. (a) If it is only decent in comparison with the previous question, it's probably still not good. There is nothing we should do (in my opinion). (b) If it is decent in comparison with many questions, I wouldn't object to reopening it. In other words: If you'd up-vote it, it's probably good enough, why not reopen it. Sure, there will be a bit of confusion in the edit history, but who goes through that to get information anyway?