It is indeed a mystery. I have never owned a densitometer. I do not know what the theoritical ideal scale of anything should be--negatives, paper, you name in. All I know is what to do to make the prints look the best (for my taste). It seems that many others, doing the same thing as I do, more or less as I do, are getting what they also think of as their best results.
There is a problem, however, for carrying what I do, too far. I use the long discontinued Super XX film, which has a far longer scale than any other film. So I'd be a bit careful. On the other hand, when I do print other's negatives in our workshops and occasionally when I invite someone to send me one, the best prints (let's for the sake of argument assume they really are the best prints and that it is not just my taste at work here), are invariably those from the densest negatives.
I believe the Ansel Adams "perfect negative" syndrome that mandates what densities negatives should have (Zone VI should be 1.10 or whatever), is the cause of a lot of "West Coast" style printing--contrasty, rather than long and smooth (and remember his recommendations were for prints made on enlarging paper). Not everyone wants to print that way.
How one makes prints is a function of one's way of being in the world. It is not an abstraction whereby there are certain desired densities to be achieved. So my recommendation is to throw away the densitometers and look at the prints. How they look is all that counts. It doesn't matter what the negatives look like according to the "authorities."